Foretravel Motorhome Forums => Foretravel Renovations => Topic started by: Merle Hench on October 24, 2011, 09:39:40 pm
Title: Converting to an on-demand water heater
Post by: Merle Hench on October 24, 2011, 09:39:40 pm
Seems I can't stop finding things I want to improve/change on my coach. :)
Currently under consideration is ditching the 6 gallon Atwood LP heater for a Precision Temp RV 500 on demand LP heater --> PrecisionTemp.com: For Recreational Vehicles and Boats (http://www.precisiontemp.com/pt_rvmd_rv500.html). Several reasons for this:
1. The one in there is a replacement, is 14 years old, and lacks electronic ignition, electric, or a heat exchanger. So when I want hot water I have to go outside with a lighter and futz around trying to get it lit. Not a happy thought on a cold, windy, rainy day.
2. I don't expect to use a lot of hot water, but when I want it, don't want to wait 1/2 an hour for it to heat up.
3. Seems wasteful to keep heating the water all the time to have it available when I need it. I plan to boondock a fair bit, and this system makes more sense to me in conserving energy.
4. If I'm connected to city water, a long hot shower is readily available.
Wondering if anyone else has done this, and if they're happy with it. The PT unit is a direct swap for a 10 gallon unit, and will require some cutting of the vertical space with a 6 gallon unit (as in my case). I don't think FT has ever installed these; looks like Aquahot is king. There is one other make of tankless water heater out there that I could find (Girard), but has a bad rep due to numerous usability issues.
Still thinking about it - would appreciate any feedback you may have. Thanks. ;D
Steve
Title: Re: Converting to an on-demand water heater
Post by: Pierce & Gaylie Stewart on October 25, 2011, 10:47:27 am
Steve,
Had thought about exactly the same thing as I have an intermittent igniter problem. Most the time it lights but sometimes not. Have checked and dbl checked all connections, etc. Plus, we dry camp 100% of the time so always looking for something more efficient.
I like the stock heater for several reasons. It heats going down the road from the engine. It has a plug-in electric heater (aftermarket) so I can heat from the generator or plug in at home and I can also bypass the propane ignition unit if the electric rod completely fails so I am not stuck without hot water out in the middle of nowhere.
It is convenient to just flip the switch next to the sink and have it light almost instantly. It does heat water for a shower in about 10 minutes if I don't take a long one. Nice to shut easily shut it off when we don't need it and don't want to listen to the racket it makes. With the heater on one side and the two furnaces on the other, it's a real noise polluter. Generator not too campground friendly either.
Title: Re: Converting to an on-demand water heater
Post by: Merle Hench on October 25, 2011, 11:13:50 am
Thanks for the reply. I've read of many instances of electronic ignition issues. Something I remember from a recent journey on the web is a gentleman who pointed out that often the ground path for the ignition is through the sheet metal and fasteners, and as corrosion develops problems abound. He grounded his ignition with a wire to a good chassis ground, and that was that.
I've always thought the heat exchanger is brilliant. Hot water when you get where you going, for free. The electric as a secondary heat source is also a good thing. With the system I'm looking at, if it doesn't light, no hot water. While I'm pretty confident I can service and repair the unit, getting parts in the boons can be a problem. I like the idea of a tankless heater relative to not using much hot water. Have concerns about water stagnating in the tank.
My backup solution at this point, and primary in good weather, is a pair of Swiss Army 5 gallon solar water bags, I plan to hang somewhere in the sun when camped. In years past I've taken many a warm or hot shower in the woods with these. Here's a good unit to order --> Swiss Military 20L (5 Gallon) Water Bag, 2 pack [445301] - $24.95 :: Colemans (http://store.colemans.com/cart/swiss-military-20l-5-gallon-water-bag-2-pack-p-2463.html). The only downside is the waiting time.
The secondary backup system is a campfire with a pot of water on a grill. ;D
The more I think about, the more it appeals to me. I guess at this point I'm looking for reasons not to convert.
Steve
Title: Re: Converting to an on-demand water heater
Post by: Dave Head on October 25, 2011, 11:29:22 am
After a recent meltdown I replaced my original 3 way Atwood with a new one. Remarkable improvement in insulation, and the electric element control design is much improved. We had to install the optional adjustable thermostat because it was so hot the mixing valve in the shower didn't work! The propane lights in an instant, and is nearly silent. Hot water from engine heat used to be available for 6-8 hours. Now 12. The insulation is now a banded styrofoam molded shell. Using the electric this trip, the propane has not lit once... I had thought of doing what you are contemplating at one time. No more.
Title: Re: Converting to an on-demand water heater
Post by: Kent Speers on October 25, 2011, 11:57:55 am
Dave, if you don't mind, what was the installed cost? Is your a 10 gallon or a 6 gallon?
Title: Re: Converting to an on-demand water heater
Post by: Rick on October 25, 2011, 12:02:00 pm
My backup solution at this point, and primary in good weather, is a pair of Swiss Army 5 gallon solar water bags, I plan to hang somewhere in the sun when camped. In years past I've taken many a warm or hot shower in the woods with these. Here's a good unit to order --> Swiss Military 20L (5 Gallon) Water Bag, 2 pack [445301] - $24.95 :: Colemans (http://store.colemans.com/cart/swiss-military-20l-5-gallon-water-bag-2-pack-p-2463.html). The only downside is the waiting time.
The secondary backup system is a campfire with a pot of water on a grill. ;D
The more I think about, the more it appeals to me. I guess at this point I'm looking for reasons not to convert.
Steve
I have used one of these in my prior camping adventures. Zodi Hot water heater
Zodi Instant Water Heater and Hot Shower - Walmart.com (http://www.walmart.com/ip/Zodi-Instant-Water-Heater-and-Hot-Shower/4698021?sourceid=1500000000000003260410&ci_src=14110944&ci_sku=4698021)
Title: Re: Converting to an on-demand water heater
Post by: Dave Head on October 25, 2011, 12:29:32 pm
Mine is a 10 gal. Best online price was Adventurer RV in Sevierville TN... I had a leak in the back and had to contract a tech to help with a shark bite fitting. As I recall it was about $650 plus 150 labor. 10 gal three way aren't cheap!
Title: Re: Converting to an on-demand water heater
Post by: Merle Hench on October 25, 2011, 05:00:50 pm
I have used one of these in my prior camping adventures. Zodi Hot water heater
Zodi Instant Water Heater and Hot Shower - Walmart.com (http://www.walmart.com/ip/Zodi-Instant-Water-Heater-and-Hot-Shower/4698021?sourceid=1500000000000003260410&ci_src=14110944&ci_sku=4698021)
That's pretty cool Rick. Does it use a lot of propane?
Steve
Title: Re: Converting to an on-demand water heater
Post by: Merle Hench on October 25, 2011, 05:17:06 pm
Mine is a 10 gal. Best online price was Adventurer RV in Sevierville TN... I had a leak in the back and had to contract a tech to help with a shark bite fitting. As I recall it was about $650 plus 150 labor. 10 gal three way aren't cheap!
Hi Dave,
Your 10 gallon is still a lot less than the unit I'm looking at, which seems to be in the $1K range. A 3 way 6 gallon is around $450 if I remember right. I've read where a 6 gal unit mandates Navy showers, while people with a 10 gallon unit were satisfied with their hot water availability.
I just wonder how much electricity these units use, and how that compares with burning propane only when hot water is needed. Using 120v to heat the tank is fine when plugged in, but off an inverter the batteries will run down sooner, requiring more frequent charging, which means more generator run time, which means I'm burning LP either way. If I had real world numbers I could make a better decision. I am planning to add solar panels in the spring, which will help keep the batteries charged.
The fridge has been changed out for an electric, so the only LP I'll be burning is the water heater, gennie, the stove, and the furnaces, which in milder climates wouldn't be used.
More reading and thinking to do, I guess. Thanks for your feedback on this.
Steve
Title: Re: Converting to an on-demand water heater
Post by: J. D. Stevens on October 25, 2011, 06:03:31 pm
Our three way water heater will not run on 120VAC from the inverter. It is wired to run from generator or shore power only. The same is true for refrigerator, hot water dispenser, air conditioners, vacuum cleaner, and block heater. That is how the coach was wired from the factory.
Title: Re: Converting to an on-demand water heater
Post by: Dave Head on October 25, 2011, 08:14:49 pm
1400 watt element
Title: Re: Converting to an on-demand water heater
Post by: Merle Hench on October 26, 2011, 06:20:00 am
Our three way water heater will not run on 120VAC from the inverter. It is wired to run from generator or shore power only. The same is true for refrigerator, hot water dispenser, air conditioners, vacuum cleaner, and block heater. That is how the coach was wired from the factory.
Yessir - mine too. I am redoing the electrical system with the addition of an inverter, which requires a subpanel. In my case, I'm looking to replace the original panel with two smaller ones. The block heater and ACs will still run on shore or gen power only. The vacuum was removed, and everything else will be powered through the inverter subpanel. The inverter will pass AC power through to the subpanel when AC power is available, and also charge the batteries. The water heater as originally supplied was an LP only model with electronic ignition and a heat exchanger.
Steve
Title: Re: Converting to an on-demand water heater
Post by: Merle Hench on October 26, 2011, 06:29:38 am
That's a lot of watts... no worries when plugged in, but that's a lot to draw from an inverter when camped. I know it isn't on all the time; the question being how many watts a day would it take, and I don't think anyone can answer that, with so many variables involved.
Need to do some more digging, methinks. Operating costs and fuel consumption are the biggest factors for me in making a choice, moreso than upfront costs.
Steve
Title: Re: Converting to an on-demand water heater
Post by: Rick on October 26, 2011, 12:02:05 pm
I have used one of these in my prior camping adventures. Zodi Hot water heater
Zodi Instant Water Heater and Hot Shower - Walmart.com (http://www.walmart.com/ip/Zodi-Instant-Water-Heater-and-Hot-Shower/4698021?sourceid=1500000000000003260410&ci_src=14110944&ci_sku=4698021)
That's pretty cool Rick. Does it use a lot of propane?
Steve
Steve, I used to share propane bottles between the stove and the shower so I don't know how many showers you can get out of a bottle. It is very efficient and will heat the water very quickly. I would go thru a couple of bottles in a season. I used to just let the water heat and recycle into the tub until the temperature was good for me and then shut off the burner and just use the pump to pump the hot/warm water. There is a stove top version that they used to make where you put the heat exchanger on a stovetop burner and heat water that way. See link for details and additional research.
enjoy hot water anytime anywhere with zodi on demand hot water and portable hot (http://www.zodi.com/Consumer/zodihotstovetopshower.html)
Title: Re: Converting to an on-demand water heater
Post by: Jeff and Victoria Moses on October 26, 2011, 12:36:39 pm
I just got an instant-on called a Hoter Instant Water Heaters HOTER-series by Shimron Energy LTD. (http://www.hoter.co.il/index.html) its a 4000 watt, gonna plumb in between gas water heater and hot supply. I'm gonna add its own cord to plug in at pedestal, only when we are on campground water. Just to save wear and tear on gas water heater.
Title: Re: Converting to an on-demand water heater
Post by: Merle Hench on October 26, 2011, 08:09:47 pm
Thanks folks.
I'm seeing a number of these smaller portable type units out there.
I keep thinking I'm seldom going to plug in anywhere, but at this point I really don't know. Am working towards a mostly self sufficient coach, at least one that can stay boondocked for a time. The less energy (and water) I use day to day, the longer I can stay put.
Still leaning toward a tankless system, but undecided at this point. There are those who love their tanked water heaters, and those that love their tankless heaters. More thinking to do...
Steve
Title: Re: Converting to an on-demand water heater
Post by: Dwayne on October 27, 2011, 09:23:39 am
I find that even when I don't turn the water on and off at the shower head while showering, the 6 gallon tank is sufficient for a nice long shower and recovery is very fast. When mine dies I intend to get a 6 gallon 3-way so I don't have to use propane when A/C is available.
Title: Re: Converting to an on-demand water heater
Post by: Pierce & Gaylie Stewart on October 27, 2011, 11:04:20 am
If you're willing to spend $70 along with some time, aftermarket 120V electric elements are available to convert almost any RV water heater. Mine was done a couple of owners ago. When connected to shore power or generator, it brings the water up to temp in about 45 minutes. Can be used at the same time as propane to cut recovery time a little. Here is the ebay site: lightning rod rv | eBay (http://www.ebay.com/sch/i.html?_nkw=lightning+rod+rv&_sacat=0&_odkw=hott+rod+rv&_osacat=0&_trksid=p3286.c0.m270.l1313) Sold under several names and prices but made you know where.
Title: Re: Converting to an on-demand water heater
Post by: Dave Head on October 27, 2011, 12:04:48 pm
And since atwoods don't need sacrificial anodes, it's a "no problem" upgrade...
Title: Re: Converting to an on-demand water heater
Post by: Merle Hench on December 15, 2011, 07:21:10 am
Greetings,
Finally decided what to do...
From what I have learned, adding an aftermarket heating element to your water heater will void most warranties. I guess it doesn't matter if the warranty is up anyway.
After further reading and searching, and much deliberation, I've decided to forego the tankless heater. One of the key issues is a single point of failure, with a product that has a limited track record. Parts availability is also a big concern. I also won't have to break out the Sawzall and cut a larger hole in the side of the coach.
I have settled on replacing the existing bare-bones Atwood 6 gal unit with another one, only this one has the electronic ignition, heat exchanger, and 120 volt heating element. No more standing outside with a lighter trying to get the pilot lit. :)
The original heater in the coach had electronic ignition only. However, the coolant hose does come through the floor right behind the heater with the shutoff valve, so should be a relatively simple matter to hook up to the heat exchanger. I am in the process of installing an inverter, so will be removing the converter. The 120 volt circuit feeding the converter just happens to run right past the water heater, through the floor, and then along the storage bay wall to an outlet the converter is plugged into. Disconnecting the feed, pulling it back to the water heater and adding an outlet box with switch provides a dedicated circuit for the heating element, which will be active only when I have shore or gen power happening.
Done deal. Steve
Title: Re: Converting to an on-demand water heater
Post by: wolfe10 on December 15, 2011, 09:37:23 am
Steve,
Not sure you want your newer inverter/charger (I assume that is what you are adding) with its higher amp draw than the OE converter AND a high amp electric heating element for the new water heater on the same circuit. Each should have its own breaker in the 120 VAC breaker box and you should verify that the wire is sized for the new load.
Brett
Title: Re: Converting to an on-demand water heater
Post by: Alfred on December 15, 2011, 11:40:17 am
Converted to a Girard unit, love it.
Title: Re: Converting to an on-demand water heater
Post by: Don & Tys on December 15, 2011, 11:58:21 am
Can you post the model number and maybe a link? Is it a tankless unit? Thanks, Don
Alfred, I had not heard of the Girard unit, so I Googled around a bit (thinking to have the information tucked away should we ever need to replace our Atwood). Like Don, I would interested in hearing more about your experience.
A good description of models and costs in on the PPL website (appears to be between $800-900 for a winter use version with replacement door): RV Tankless Water Heater from Girard - PPL Motor Homes (http://www.pplmotorhomes.com/parts/rv-water-heaters/rv-tankless-water-heater.htm)
I then found a rather informative post from last March on RV.net and learned a bit more about controlling the temperature (I'll paste the post below). Now... not so sure... but will be interested to hear Alfred's experience.
* Turn the Power switch to ON * Set the Mode Switch to Auto * Open a hot water faucet * Adjust the flow to achieve the desired temperature * Gradually DECREASE the Water Flow to RAISE the temperature. * Gradually INCREASE the Water Flow to LOWER the temperature.
*By manually setting the MODE switch to automatic, the model GSWH-1 automatically senses and adjusts the flame level (High or Low) depending on the temperature of the inlet cold water (the water coming into the GSWH-1). The flame will change from High to Low if the temperature of the inlet water goes above 70°F and will switch back to High when the inlet water goes below 65°F. Manually switching the Mode switch from AUTO to LOW overrides the automatic function and forces the flame to stay in LOW even if the inlet water is less than 65°F. This can be desirable when the cold water inlet temperature is very cold and the inlet water pressure is below 1.0 gpm which could result in limiting (see Notice below). The system will remain in Low until manually switched to Auto.
Basically the puppy delivers two differing amounts of heat energy to the water - a fixed but low level of heat energy to incoming water whose temperature is over 70F, and a different & higher, but still fixed, amount of heat energy when the incoming water temperature is under 65F.
A user varies the temperature as delivered from the shower head by increasing or decreasing the flow rate of the delivered water, not by changing the settings of the cold and hot water settings on the shower control.
I.e., forget about getting a high volume of hot water for a nice relaxing shower in a Wildcat Sterling 5th wheel, or any other RV with a Girard tankless hot water system. It won't happen. You can get only a moderate or low flow of hot water, though you can get the hot water as long as the propane holds out.
I have read posts (perhaps on this board) explaining how to get a decently long hot water shower with a hot water heater which uses both propane and electricity to heat the water. You just have to turn both heat sources on simultaneously, right before the shower. The two heat sources will rapidly heat up the incoming replacement cold water entering the hot water tank. You must, however, remember to turn off one of those heat sources after your shower is over.
Basically we're stuck with "Navy" type showers in RV's. Wet yourself up, turn the water off, lather up, turn the water back on to rinse off, and then turn the water off. Soaking in a nice long hot shower requires not merely an external water hookup, but also either some effort and possible mistakes with the controls of a hot water tank, or a relatively low flow of water from a tankless hot water system. Both will eat a lot of propane.
Title: Re: Converting to an on-demand water heater
Post by: Alfred on December 15, 2011, 12:13:20 pm
Here's the Link; Girard Water Heater - Girard Products, LLC | Tankless RV Water Heater | On (http://greenrvproducts.com/girard-tankless-rv-water-heater/)
Be sure to connect the engine hot water hoses together and turn off valve. Use adjustable water pressure regulator set at 50-55psi. Install Oxygenics Body & Spa Shower Head After messing up my back several days ago, I find a lenthy hot shower to be needed these cold mornings to get going. I love this heater.
Title: Re: Converting to an on-demand water heater
Post by: Merle Hench on December 15, 2011, 12:24:59 pm
Not sure you want your newer inverter/charger (I assume that is what you are adding) with its higher amp draw than the OE converter AND a high amp electric heating element for the new water heater on the same circuit. Each should have its own breaker in the 120 VAC breaker box and you should verify that the wire is sized for the new load.
Brett
Hi Brett,
Perhaps I didn't explain myself well. The inverter is getting power from a 10/3 cable (common trip 30 amp breaker) from the main panel, and a 10/3 cable returns from the inverter to feed a subpanel. The original electrical panel is gone, replaced by two new panels.
What I'm thinking is to completely remove the original converter, and use that AC circuit (20 amps) to power the water heater (dedicated only to the water heater). With the converter gone, seemed like a good use for an otherwise unneeded circuit.
Do appreciate your concern and thoughts. Thank you.
Worth mentioning - the original panel had an aluminum bus, and I noted on one the hot legs going on, and a few of the wires coming off the breakers - oxidization. The copper wire end was turning black. I showed an electrician friend this and asked about it. He told me it's the result of the dissimilar metals. The new panels have a copper bus.
Steve
Title: Re: Converting to an on-demand water heater
Post by: Merle Hench on December 15, 2011, 12:42:52 pm
Re: The Girard tankless heater - I did a lot of reading on the different types of RV water heaters available, and what I found was a lot of people were very unhappy with the Girard heater, the big complaint being that you have crank up the flow to lower the temperature, instead of mixing in cold water. Many felt this was too wasteful of water when boondocked, and most folks went back to a tank heater. I have no direct experience so cannot say one way or another. If you google "Girard water heater problems" you'll find a lot of threads posted.
The big complaint with the Precision Temp unit was performance on a windy day. Makes ordering the optional wind cover mandatory. Most people seemed happy with them; some had repeated issues that led them to chuck them as well. Most people seemed to agree a tankless heater was not suitable for boondocking. Again, no direct experience myself.
What swayed me back to the Atwood unit was the 3 way heating capability. If I'm plugged in, I don't use propane to heat the water. That, and parts are readily available from numerous sources. Lastly, it's less than half the price of a Precision Temp unit. Just seemed the best choice overall.
Steve
Title: Re: Converting to an on-demand water heater
Post by: Don & Tys on December 15, 2011, 12:58:07 pm
Thanks for that perspective Steve! Since my own water heater is out right now and is 12 years old, we are probably going to put a new one in and are considering the idea of on demand units. I have one in my house and have grown attached to it... Setting th temperature and not having to juggle the cold water mix is such joy. Sounds like the RV units don't work that way... Don
Re: The Girard tankless heater - I did a lot of reading on the different types of RV water heaters available, and what I found was a lot of people were very unhappy with the Girard heater, the big complaint being that you have crank up the flow to lower the temperature, instead of mixing in cold water. Many felt this was too wasteful of water when boondocked, and most folks went back to a tank heater. I have no direct experience so cannot say one way or another. If you google "Girard water heater problems" you'll find a lot of threads posted.
Title: Re: Converting to an on-demand water heater
Post by: Gayland Baasch on December 15, 2011, 01:08:32 pm
Don - is the plumbing there to hook up to the engine heat?
Title: Re: Converting to an on-demand water heater
Post by: Peter & Beth on December 15, 2011, 01:09:32 pm
The Atwood three way WH in the 97 U270 is OEM and works like a top. It is 10 gals. and I've never run out of hot water taking very long showers whether using the electric or propane feature. I'm very satisfied with its performance.
(edit): The electric heating element was replaced by FOTn in 2003 when I purchased the coach with a 6 month warranty. It has been performing as expected since.
Title: Re: Converting to an on-demand water heater
Post by: Don & Tys on December 15, 2011, 01:21:26 pm
Yes, ours has the heat echanger on it. Through a bucket miscalculation, I lost about 2 gallons of coolant! Oh well, I guess it is time to change it anyway... Don
Don - is the plumbing there to hook up to the engine heat?
Title: Re: Converting to an on-demand water heater
Post by: Jerry Whiteaker on December 15, 2011, 02:43:43 pm
Wow, lot of posts on this subject. I skimmed through most of them, but didn't see any mention of how big a gas line connection is required for a tankless or on demand heater. I thought about installing a tankless water heater using natural gas in the house, but didn't do it as it required an increase in the size of the gas pipe to the heater. A major job as the gas pipe went down inside a wall from the attic to the bottom floor (2 floors). A motorhome should not be as difficult to re-plumb if required, but maybe a consideration. If you are wondering why the gas line is in the attic; that's where the furnace and air handler for air conditioner are located. After the furnace the gas line branches off to other appliances (stove, fireplace, water heater).
Title: Re: Converting to an on-demand water heater
Post by: Dave Cobb on December 15, 2011, 09:44:14 pm
Gas line size is very important, I learned. I suffered with a too small a supply line on my home unit, till I re-read and got the major large required size flex piping. Not sure I am ready for a on demand in the coach, as it will encourage the running of water, which is usually tank water for us. We tend to fill and use the tank on most short trips. Refilling when we run out, or are headed out of the campground.
Title: Re: Converting to an on-demand water heater
Post by: Merle Hench on December 16, 2011, 07:19:08 am
Thanks for that perspective Steve! Since my own water heater is out right now and is 12 years old, we are probably going to put a new one in and are considering the idea of on demand units. I have one in my house and have grown attached to it... Setting th temperature and not having to juggle the cold water mix is such joy. Sounds like the RV units don't work that way... Don
Hi Don :),
Something you can add to your coach that I spotted the other day, while searching for a kitchen faucet, is a shower mixing valve that regulates the temperature, so once you get it where you want it, it will keep it there. Did not appear to be any bigger than a standard mixing valve. Don't have a link, but I saw it on Amazon.
It has occurred to me that a common cold weather irritation in the stick and brick with regards to showers is waiting for the hot water to get hot, and then having to keep cranking it warmer as the cold water lines empty out of room temperature water and outside (cold) water is drawn in. I don't see this being the case in the coach, as the plumbing distances are much shorter than in a house.
I like the idea of an on-demand heater, but just don't see it as ready for primetime for RVs. For peace of mind, I'm going with something that has a proven track record and happy owners.
Here's an idea I've been toying with - RV solar water heating. Water is circulated from your hot water tank to a roof-mounted solar collector/heat exchanger and pumped back into the tank. A thermostat regulates temps. A small pump attached to the tank does the circulating. Might not work well in colder weather (heat loss too great), but would save power in warmer weather. Of course, a leak in the system could be a disaster, and freezing weather would also be a consideration. Something portable might work. Will think on that some more.
Steve
Title: Re: Converting to an on-demand water heater
Post by: Peter & Beth on December 16, 2011, 10:07:27 am
I've heard of folks collecting the shower water in a bucket until the water gets to temperature. This collected cold water is then used for toilet flushing/washing dishes, anything that does not need potable water.
Title: Re: Converting to an on-demand water heater
Post by: wolfe10 on December 16, 2011, 10:22:55 am
Peter,
We routinely did that on the sailboat. With every gallon (remember, 8.3 pounds per gallon) of water having to be hauled out to the boat in the dingy, hoisted onto deck and poured into tank fill, one learns very quickly to be conservative with water use OR becomes very strong from the weight training.
Title: Re: Converting to an on-demand water heater
Post by: wa_desert_rat on December 16, 2011, 01:14:44 pm
We routinely did that on the sailboat. With every gallon (remember, 8.3 pounds per gallon) of water having to be hauled out to the boat in the dingy, hoisted onto deck and poured into tank fill, one learns very quickly to be conservative with water use OR becomes very strong from the weight training.
Not to mention from rowing around to every other boat in the anchorage borrowing 5-gallon jugs. 70 gallons of water requires more jugs (14 or so) than you can conveniently carry on a 30-something sailboat.
We solved part of the water issue by using a 2-gallon spray tank. We heated a gallon of water to a nice temperature on the stove, filled most of the tank, pumped it up a few times, and took a shower. We could both take a shower in one fill-up. If the ocean water (and air temps) were warm enough we'd soap up with the tank, rinse by jumping over the side, and then rise off the salt with the tank.
And if we got a nice rain shower we all headed topsides!!!
Craig
Title: Re: Converting to an on-demand water heater
Post by: Gary Bouland (RIP) on December 16, 2011, 02:35:20 pm
And we thought we had it tough with a FT that carries 100 gallons of fresh water ..... Maybe I won't consider a yacht after all. :) :) :) :) Gary B
Title: Re: Converting to an on-demand water heater
Post by: Don & Tys on December 16, 2011, 03:22:07 pm
Thanks for the suggestions Steve, I believe that Dave K. Posted a how to on the balancing mixing valve... I will have to look into that option. I am not sure I even understand what it does VS. an ordinary mixing valve, but it sounds cool! Or hot:). Speaking of water heaters, I pulled the drain plug on mine (or what I thought was the drain plug!), and there is something still in there that seems like it will never come out. I wonders if maybe it is some sort of check valve, or? Got nothing! Here is pic of it, anybody know what it is? Since our 3-way water heater was working when I took it out, if I could be sure the tank was good, I would think about getting new Styrofoam insulating kit for it, clean it out really well and put it back in. On the other hand, it is a lot of work and maybe the peace of mind of having a new unit before beginning full timing might be worth the expense (about $600 for a new 10gal 3-way with heat exchanger). Any comments?
Something you can add to your coach that I spotted the other day, while searching for a kitchen faucet, is a shower mixing valve that regulates the temperature, so once you get it where you want it, it will keep it there. Did not appear to be any bigger than a standard mixing valve. Don't have a link, but I saw it on Amazon.
Title: Re: Converting to an on-demand water heater
Post by: JohnFitz on December 17, 2011, 12:20:36 pm
Don, PO must have installed a plug with an zinc anode on it. The anode deteriorated to the point where it's disconnected from the plug and is stuck in the hole. I would just push it through into the tank, do a flush with one of those clean-out wands and reinstall the plug. There's other thread conversations about this but you really don't need an anode for the Atwood tanks. The anode should eventually totally dissolve and you will see it come out as you do flushes of the tank.
Title: Re: Converting to an on-demand water heater
Post by: Don & Tys on December 17, 2011, 03:29:23 pm
Thanks John, Reading up on the Atwood anode thing... Found out that the anode for aluminum tanks should be magnesium vs zinc. I will try soaking with a vinegar solution (as suggeted to me by another forum member) for awhile and see if it loosens up. The WH is out right now and it will be awhile before I will be ready to reinstall the old one or put a new one in, so not in a rush ATM. Don
Title: Re: Converting to an on-demand water heater
Post by: Dave Katsuki on December 18, 2011, 12:07:51 am
On saving shower hot water when boondocking: Dick Ward posted a mod about a year ago (I think) that added a timer and valves and plumbing to circulate water from the hot water taps on the shower and the lav back to the fresh water tank, so when you were going to take a shower, you would trigger the timer and all the hot water in the lines would be sent back to the tank for some set-able period until ready for a shower. Very clever solution for boondocking!
Adding a circulating pump for quicker hot water (http://www.foreforums.com/index.php?topic=10953.msg53114#msg53114)
It's somewhere down on my to do list...
Title: Re: Converting to an on-demand water heater
Post by: Dave Katsuki on December 18, 2011, 12:29:12 am
Thanks for the suggestions Steve, I believe that Dave K. Posted a how to on the balancing mixing valve... I will have to look into that option. I am not sure I even understand what it does VS. an ordinary mixing valve, but it sounds cool! Or hot:). Speaking of water heaters, I pulled the drain plug on mine (or what I thought was the drain plug!), and there is something still in there that seems like it will never come out. I wonders if maybe it is some sort of check valve, or? Got nothing! Here is pic of it, anybody know what it is? Since our 3-way water heater was working when I took it out, if I could be sure the tank was good, I would think about getting new Styrofoam insulating kit for it, clean it out really well and put it back in. On the other hand, it is a lot of work and maybe the peace of mind of having a new unit before beginning full timing might be worth the expense (about $600 for a new 10gal 3-way with heat exchanger). Any comments?
Don,
I would replace it if I were you. We had our original heater (same as yours) develop a leak about 2 years ago, and I replaced it with a new one. Couldn't get the model with a heat exchanger delivered in time to meet our travel schedule, and I went with a 2-way (120V + propane), which has been fine. The styrofoam insulation on the new ones keeps water plenty hot all day while we're travelling. BTW- Atwood says not to use an anode on their tanks. - Not needed since they are aluminum. And BTW2 - reconnecting it with reinforced flex hose, (instead of PEX,) makes the installation a whole lot easier!
Title: Re: Converting to an on-demand water heater
Post by: Neal Pillsbury on December 18, 2011, 02:46:35 am
The Atwood three way WH in the 97 U270 is OEM and works like a top. It is 10 gals. and I've never run out of hot water taking very long showers whether using the electric or propane feature. I'm very satisfied with its performance.
I agree wholeheartedly, Peter. The Atwood 10 Gal. Aluminum units, treated and cared for properly, are another reason that the U270's shine in their simplicity and longevity. We've never had a complaint or problem with ours in 12 years. A mud dauber screen (and simple cleaning annually) and it's good to go, never short of hot water on or off the road. One issue that many ignore is NEVER consider a sacrificial anode of any flavor, Magnesium OR Zinc. I know the unit won't last forever, but exactly the same unit will be my first choice when I need to replace it.
................Speaking of water heaters, I pulled the drain plug on mine (or what I thought was the drain plug!), and there is something still in there that seems like it will never come out. I wonders if maybe it is some sort of check valve, or? Got nothing! Here is pic of it, anybody know what it is? .................................................
Don, Your previous owner did you an unintentional disservice, removed the NYLON (or maybe it is TEFLON) drain plug and installed a sacrificial zinc (mostly aluminum) anode in the the drain fitting. That is in direct conflict with the ATWOOD owner's manual for our three way heaters. The aluminum/zinc fitting story is as follows: The aluminum/zinc sacrificial anode provides very little driving current to protect an aluminum tank, especially when softer water happens to be in the tank, so it isn't providing any protection to speak of...........it is just creating issues as follows:
The AL/ZN anode produces about 1000 times it's volume in corrosion byproducts
That's just junk that sits in the tank or gets deposited downstream in all the pinch points/ wrong places
The original AL/ZN anode starts to expand the day anyone installs it and it becomes hard, if not impossible to remove it (what you've experienced)
The AL/ZN anode crumbles off the center core mounting rod, junking up the bottom of the heater and the mounting rod itself becomes weak and sacrificial (again, what you've experienced)
Free aluminum molecules/radicals get carried along in the hot water stream and they do all kinds of ugly things to liver, brain, kidney, spleen and neural systems
All because someone wanted to be a good guy and protect the aluminum shell of the heater (in contradiction with the OEM's directions).
I don't believe vinegar will dissolve it. If it were me , my choices would be:
If I could grasp the broken anode core rod with needle nosed vise grips, I'd keep gently working on it (it may be soft enough to yield the expanded material enough to work it back out of the drain opening). Then I'd thoroughly flush the sacrificial junk out of the tank each month, for several months.
If that doesn't work, replace with a new Atwood of same model
You also have the option of pushing the broken anode through and then just try to minimize the ingestion of any of the hot water (use only cold water for cooking after flushing any residual hot water from the common plumbing (before each cold water cooking use). Good Luck and Merry Christmas to all!
Neal :)
Title: Re: Converting to an on-demand water heater
Post by: Don & Tys on December 18, 2011, 02:31:44 pm
Thanks Neal! Excellent and informative post as usual. I think we are just going to replace it with another 3 Way Atwood of the same model. Too bad the PO decided to add an anode... I will salvage the electronics etc. from the old one for spares. It is just too much hassel to put the old one back in and have to deal with all the gunk in it and the possibility of it starting to leak etc. I like the styrofoam insulation on the new ones. Looks much more "tidy" than the cardboard box around the old one. Don
Title: Re: Converting to an on-demand water heater
Post by: Don & Tys on December 18, 2011, 06:11:55 pm
Dave,
We have decided to replace the WH. Looking forward to the improved performence via the styrofoam insulation. What kind of flex hose did you use? The fittings on the both the old heater and on the manibloc appear to be pipe thread, while those braidied stainless steel hoses typically used for home washer hook up use garden hose type thread. Were these one you made yourself to length? If not how long were the ones you used?
I would replace it if I were you. We had our original heater (same as yours) develop a leak about 2 years ago, and I replaced it with a new one. Couldn't get the model with a heat exchanger delivered in time to meet our travel schedule, and I went with a 2-way (120V + propane), which has been fine. The styrofoam insulation on the new ones keeps water plenty hot all day while we're travelling. BTW- Atwood says not to use an anode on their tanks. - Not needed since they are aluminum. And BTW2 - reconnecting it with reinforced flex hose, (instead of PEX,) makes the installation a whole lot easier!
Title: Re: Converting to an on-demand water heater
Post by: JohnFitz on December 18, 2011, 08:00:43 pm
Don, I used braided hose on mine as well when I replaced the WH. Home Depot (or Lowes) should have ones that have NPT on both ends. I don't remember the length I used but they are long enough such that you can set the WH on a stool (face down) and make all the connections. Then it's just a matter of inserting it in without pinching wires or hose. I think I had to re-tighten the fittings again after the first use of the new unit - the rubber seals relaxed a bit and I had some minor drips - it's been good ever since. Another thing that might be different on the new unit is how the AC element is turned on. The old one was independent of the gas control ( lighted AC switch at the foot of the bed). The new one uses the gas control circuit board with a second 12 volt switch (first switch being for gas).
I replaced mine in 2006 with a 3 way. I don't think the "motor assists" is very good on the new ones. It's just a short aluminum tube welded for a couple of inches to the tank. If I remember correctly the old WH had a tube that went inside one end and out the other. In practice the new unit doesn't seem to heat the water nearly as much as the old unit. I wouldn't think twice about just using a 2 way unit next time. Maybe others have had better experience with the new motor assist.
Title: Re: Converting to an on-demand water heater
Post by: Don & Tys on December 18, 2011, 10:11:18 pm
Thanks John, that is helpful. I will look for the NPT threaded braided hose at Home Depot. I definitely see how much easier that will make the install! Don
Title: Re: Converting to an on-demand water heater
Post by: Dave Head on December 19, 2011, 12:04:38 am
Various length NPT braided hose from Home Depot - just like you would use on a sink, etc... I had a tough time getting one fitting to stop leaking on the house side piping, and we ended up replacing it with a shark bite fitting.
The 'winterize bypass system' on the back of my old heater was worn out and the valves hadn't worked for years (I honestly didn't even know they were there). Since we are in FL and would never need to winterize anyway I elected to not duplicate the system.
Title: Re: Converting to an on-demand water heater
Post by: Dave Head on December 19, 2011, 12:08:18 am
The motoraid works as well on the new one as the old. It heats up quickly and the Styrofoam casing holds the heat in very well - far better than the original spun fiberglass roll. I can have hot water 6-8 hours.
Title: Re: Converting to an on-demand water heater
Post by: Don & Tys on December 19, 2011, 12:14:24 am
That is indeed good to hear! Wish I could find a cut away view of the Atwood tank with the heat exchanger... We will definitely replace our unit with a three way. Don
The motoraid works as well on the new one as the old. It heats up quickly and the Styrofoam casing holds the heat in very well - far better than the original spun fiberglass roll. I can have hot water 6-8 hours.
Title: Re: Converting to an on-demand water heater
Post by: Dave Katsuki on December 19, 2011, 12:48:02 am
We have decided to replace the WH. Looking forward to the improved performence via the styrofoam insulation. What kind of flex hose did you use? The fittings on the both the old heater and on the manibloc appear to be pipe thread, while those braidied stainless steel hoses typically used for home washer hook up use garden hose type thread. Were these one you made yourself to length? If not how long were the ones you used?
Thanks, Don
Don,
I did just what JohnFitz did for the braided hose. Readily available from Lowes or Home Depot. Our coach has the 120V switch at the foot of the bed, and I just wired the 12V control line for 120V heating to be on all the time. That way, we aren't confused about how to turn 120V heater on and off, and I didn't have to wire in a new 12v control switch!
Title: Re: Converting to an on-demand water heater
Post by: Dave Head on December 19, 2011, 08:49:41 am
I would be surprised if it changed much. I compared my old tank to the new one and they were virtually identical event though they were 17 years apart. Controls were handled differently, especially for the 120V heater, is all.
Title: Re: Converting to an on-demand water heater
Post by: Bill Willett on December 19, 2011, 10:48:14 am
Make sure you check the inside diameter of the braided hose, there is a big difference between it and pex. ^.^d
Title: Re: Converting to an on-demand water heater
Post by: lgshoup on January 01, 2012, 11:53:38 pm
I put in an RV 500 tankless and couldn't be happier. Got tired of problems with AquaHot and when it developed a leak that required complete replacement I did the change. Our '96 U-295 didn't have a regular water heater so I put it on a shelf just above the water pump in front of the right rear wheels. Cut through the bus door for the vent cover and put the heater as close to the door as I could before screwing it down. All the hot water we want and need to adjust to some cold for showers or it's too hot!
Title: Re: Converting to an on-demand water heater
Post by: Don & Tys on January 02, 2012, 12:48:37 am
Hi Larry! Welcome to the Forum. That is a nice coach you have! It was great seeing it and talking to you today. I was impressed with your water heater installation... very clean job. We may go that route when it is time put her back together after the bulkhead repair. Regards, Don & Tys
Title: Re: Converting to an on-demand water heater
Post by: Duane Budd on January 02, 2012, 07:58:00 am
So what are you using to heat the coach?
Title: Re: Converting to an on-demand water heater
Post by: lgshoup on May 18, 2012, 09:11:04 pm
Electric when it's available and included, otherwise, we try to stay where it's warm. Our coach is one of those with wheels so it rolls down south pretty easily.