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Topic: Converting to an on-demand water heater (Read 3578 times) previous topic - next topic

Re: Converting to an on-demand water heater

Reply #20 –
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

Re: Converting to an on-demand water heater

Reply #21 –
Converted to a Girard unit, love it.

Re: Converting to an on-demand water heater

Reply #23 –
Quote from: Alfred –
Converted to a Girard unit, love it.
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

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.

The Girard Tankless Hot Water Heater tips are:

Operating Tips - Girard Products, LLC | Tankless RV Water Heater Operating Tips

In Summary,

* 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.

Re: Converting to an on-demand water heater

Reply #24 –
Here's the Link;
                  Girard Water Heater - Girard Products, LLC | Tankless RV Water Heater | On

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.

Re: Converting to an on-demand water heater

Reply #25 –
Quote from: wolfe10 –
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

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

Re: Converting to an on-demand water heater

Reply #26 –
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

Re: Converting to an on-demand water heater

Reply #27 –
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
Quote from: Merle Hench –
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.

Re: Converting to an on-demand water heater

Reply #28 –
Don - is the plumbing there to hook up to the engine heat?

Re: Converting to an on-demand water heater

Reply #29 –
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.

Re: Converting to an on-demand water heater

Reply #30 –
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



Quote from: Gayland Baasch –
Don - is the plumbing there to hook up to the engine heat?

Re: Converting to an on-demand water heater

Reply #31 –
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).

Re: Converting to an on-demand water heater

Reply #32 –
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. 

Re: Converting to an on-demand water heater

Reply #33 –
Quote from: acousticart –
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

Re: Converting to an on-demand water heater

Reply #34 –
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.

Re: Converting to an on-demand water heater

Reply #35 –
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.

Re: Converting to an on-demand water heater

Reply #36 –
Quote from: wolfe10 –
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.

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

Re: Converting to an on-demand water heater

Reply #37 –
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

Re: Converting to an on-demand water heater

Reply #38 –
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?
Quote from: Merle Hench –

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.

Re: Converting to an on-demand water heater

Reply #39 –
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.