Hot water heater

Topic: Hot water heater (Read 1771 times) previous topic - next topic

Hot water heater

August 15, 2017, 07:32:33 pm

Our coach has a propane-only hot water heater. I just looked at the specs and didn't see anything about a hot water heater. I suspect that the unit I have is from the factory, so I'm thinking that someday I'm going to need to replace it.

Questions:
1. How difficult will it be to replace this with an electric and propane unit?
2. Where would the electric power come from?
3. Is it possible to increase the capacity of the hot water heater? I'm thinking about going from an assumed six gallons to maybe 8-10 gallons.
4. Any specific suggestions for brand/models to consider?
5. Is this a DIY project or should I plan on having OTM do it?

Again, this isn't going to be something that happens this weekend, but probably sometime in the next year. Of course, if it dies on me I'll have to take care of it immediately, but I'm hoping that I've got some time yet.

Re: Hot water heater

Reply #1 – August 15, 2017, 07:36:30 pm

Usually the U300s came with 3 way 10 gallon units. Engine heat, propane and electric.

Re: Hot water heater

Reply #2 – August 15, 2017, 07:42:41 pm

What is the model of the water heater? You should be able to tell what size it is by the model number. You can check if there is a 120 volt receptacle near that might work or else you would have to run a wire from the breaker panel to the water heater. This can be a DIY project. If yours has the electronic ignition, the new Atwood does have a little different wiring system than the vintage you have, but comes with great directions.

Re: Hot water heater

Reply #3 – August 15, 2017, 07:54:43 pm

My 93, U300 has a six gallon water heater. According to PPL the replacement for my model GH6-7E Atwood water heater is a GH6-8E. I am waiting on a response from Atwood to confirm this is a direct replacement. I don't need an electric element so I will just replace the Porpane/engine heater type that we now have.

Re: Hot water heater

Reply #4 – August 15, 2017, 08:02:36 pm

Model number is GH6-7E, 6.2 gallons. Didn't see a brand name on it. I don't see anything that looks like an electric heating element, nor have I ever found a switch for one. Yes, I think it has the motor-aid assist. At least, there is an insulated pipe with a valve on it right there. Don't know if I'm getting engine heat or not, as we just leave the propane on all the time.

Re: Hot water heater

Reply #5 – August 15, 2017, 08:04:58 pm

Drain plug can be replaced with 115V heater element

Re: Hot water heater

Reply #6 – August 15, 2017, 08:38:58 pm

David,

If your water heater is mounted like mine, you will find it is supported by a section of the steel frame structure. I remember reading on the Forum that a larger (10 gal) heater won't fit in that space without removing and repositioning that steel support beam. This, of course, would require expertise in welding in very tight quarters. That may be a factor in deciding if a larger 10 gal heater is a "do-it-yerself" project.

Tim mentions the 115V heating element that replaces your drain plug. A year ago, I stuck one of those in our original factory installed water heater. We have been very happy with it. If you have any interest in reading about that option, here is my thread:

Hott Rod Installation, Atwood GH6-7E

Re: Hot water heater

Reply #7 – August 15, 2017, 09:26:27 pm

David,

The Atwood GE9-EXT 6 gal gas and electric DSI may work in our situation without a lot of modification. It's supposed to give you the equivalent of 9 gals. in the same space as the 6 gal. by combining hotter water with cold water in a special mixing valve to get the temperature down. There is also a tankless but this one may be easier to install in the same space. Atwood GE9-EXT Gas and Electric XT 6 Gallon DSI Water Heater 90071 Camper...

Jerry

Re: Hot water heater

Reply #8 – August 15, 2017, 09:33:05 pm

I would be surprised if your U300 did not come with the electric originally - I always thought it was standard on the U300. I suppose the original owner opted to not have it.

Is there a breaker on the electric panel under the bed with a "water heater" label on it? There should also be red switch at the foot of the bed too (not far from the engine block heater) with a "water heater" label.

If the heater is really original, the electric hook up to it is in the very back where it's almost impossible to reach without pulling the heater. It's completely independent of the gas portion with it's own thermostat, circuit breaker button and a small toggle switch. Some coaches have a hold drilled in the bulkhead wall with the storage compartment where you can peek in with a flash light to the back of the water heater.

Re: Hot water heater

Reply #9 – August 15, 2017, 09:39:29 pm

Quote from: JohnFitz – August 15, 2017, 09:33:05 pm

If the heater is really original, the electric hook up to it is in the very back where it's almost impossible to reach without pulling the heater. It's completely independent of the gas portion with it's own thermostat, circuit breaker button and a small toggle switch. Some coaches have a hold drilled in the bulkhead wall with the storage compartment where you can peek in with a flash light to the back of the water heater.

Can the element be changed without removing the unit from the coach?

Re: Hot water heater

Reply #10 – August 15, 2017, 09:58:19 pm

No switch at the foot of the bed and no breaker in the panel.

Thanks for the links. Looks like I've got a bit of research to do. If you have one of those tankless hot water heaters, how well do you like it? I'm guessing that they are more expensive than the others, but if they really do give lots of hot water the CFO might be willing to spring for one.

Re: Hot water heater

Reply #11 – August 15, 2017, 11:09:41 pm

David, our coach came from the factory with a 10 gallon Atwood (aluminum tank) propane-only hot water heater.

When it came time to change it out we used a standard model Atwood 10 gallon heater with 120volt heater. Original and new heaters are same size and configuration.

All coaches can benefit by adding the electric heating element feature. Additional cost is manageable, heating element can be a good generator load, most campground have enough electric capacity to electric heat water, much quieter when heating water, saves propane, has two options in case a component failure, etc. We think it a missed opportunity to add a new heater without electric. The new electric part of the project can even be completed long after the unit is installed and functioning.

Integrated electric heating is better than after market electric elements, like drain plug heaters, as the temp control thermostat is also integrated, and not an add-on where it can be difficult to measure tank temperature.

For adding electric power, we cut off the female end of a heavy duty extension, connected the wires to heater and plugged the male end into a bay outlet that is not connected to inverter.

Certainly can be a do it yourself project if one is handy. When you are ready to do the job, there is info on the Forum and BeamAlarm.com to show what others including ourselves have done.

In your planning and research, you may want to examine & upgrade the other associated plumbing at the same time, including the pipes in and out of the heater. This could be a time to include heater bypass valves for use in case heater breaks or coach needs winterizing.

Re: Hot water heater

Reply #12 – August 15, 2017, 11:32:56 pm

Quote from: FourTravelers – August 15, 2017, 09:39:29 pm

Can the element be changed without removing the unit from the coach?

Not in my opinion. It's hard enough just to reach up in there and you can't see.
Flip a switch, reset the button breaker, sure. Replace the element, no.

In this thread (reply #46) I discuss how I have tried to make it easier to remove and install the heater: Converting to an on-demand water heater

Re: Hot water heater

Reply #13 – August 16, 2017, 10:32:42 am

We also have the Hott Rod drain plug heater. No thermostat but it never seems to get hot enough to need it. In a desert rainstorm, some rain got on it and triggered the GFI. That took almost an hour to figure out what had caused the problem.

Pierce

Re: Hot water heater

Reply #14 – August 16, 2017, 12:23:13 pm

I just replaced mine. Piece of cake, but I replaced with the same model. The electric element can be changed from the back without removal. To run 110V you would need to install it's own circuit breaker and run wire but seems easy enough for me.

Some Grand Villas came with 110 electric, some did not.

Re: Hot water heater

Reply #15 – August 16, 2017, 07:44:35 pm

David you have a 6 gallon Atwood water heater.

Re: Hot water heater

Reply #16 – February 18, 2018, 02:26:20 pm

Just bought a 1994 Grand Villa and am going through the systems some how I have hot water but the propane heater does not ignite how does this system work

Re: Hot water heater

Reply #17 – March 02, 2018, 08:32:32 pm

Hi,
Stick with the Atwood H2O heaters. I don't believe FT has ever used anything else for their propane heaters. Install size requirements should be available online.

To tomklein: If the heater isn't igniting it could be air in the propane line or a bad electronic ignition sparker, (if so equipped). Replacements for Atwood ignition are available. Also check the fuse. Sometimes it is that simple.

A general side note: I was always told to put an anode drain plug in RV water heaters to prevent corrosion of the tank. Recently learned that Atwood does not recommend an anode because their aluminum tank is, "not being as susceptible to corrosion". I'm thinking any chance of corrosion is too much. I have previously had an aluminum Atwood H2O heater tank corrode out in a travel trailer. Not cheap to replace. And the water damage from a slow leak can be significant. I feel it is very important with my current rig, 2002 U270, to keep the basement dry. Critical to keeping intact the basement bulkhead.

Have read elsewhere on the forum that cleaning the H2O tank, flushing it out as regular maintenance makes for a long heater life. Some folks have made spray wands to put inside tank through the drain plug. Forces out any scale or bits of debris. This seems to be more important when the electric heater option is used a lot. The mineral content of the water is also a factor.

My choice for now is to go without the anode for my Atwood and always do a yearly flush/cleaning of the heater tank. Part of my regular inspection procedure.

Re: Hot water heater

Reply #18 – March 03, 2018, 10:44:53 am

Quote from: tomklein – February 18, 2018, 02:26:20 pm

Just bought a 1994 Grand Villa and am going through the systems some how I have hot water but the propane heater does not ignite how does this system work

Yours is a two way water heater that, with a little work, can be made into a three way heater. You have hot water while driving as this model heater has a heat exchanger inside with the engine coolant running through the heater while driving. Follow the older posts or go online to check all your connections and sensors. The sensor kit is cheap. Failing that, a new Dinosaur circuit board will do the trick. See: Dinosaur Electronics Home. High quality circuit boards for RV appliances. Note that it has about a 6 to 10 second delay so don't be alarmed if the heater does not spring into immediate action.

You can pull the drain plug on the bottom and install a "hot rod" 110V heating element into the heater. Ours had one the previous owner had installed. They work OK if on shore power but a rain storm may cause the GFI that you have wired it into to trip. Don't ask me how I know (after an hour of scratching my head). Hott Rod Water Heater Conversion Kit - 6 Gallon - Diamond HR6 - Water...

Pierce

Re: Hot water heater

Reply #19 – March 03, 2018, 12:25:46 pm

I just replaced my 10 gal Atwood three way water heater.

The propane system is controlled by two temperature sensors which are held against the tank on the outside, plus an overheat fuse on the input 12 volt wire (white in coach wiring harness connected to brown in tank wiring). If the inline fuse has blown due to overheat, it must be replaced. If one of the temperature sensors is open circuited, it must be replaced. For the propane to fire, four items must be good: the inline overheat fuse. the temperature control (140F cutout), the second temperature control, and the switch in the kitchen. Check for 12v on the brown wire in the connector block (after removing it) with the hot water tank switch in the kitchen turned "ON".

The second led light near the switch in the kitchen is fed by the tank blue wire which is connected to a black wire in the coach wiring harness. The propane heater will work even if this light does not turn on.

Re: Hot water heater

Reply #20 – March 03, 2018, 12:31:54 pm

If you have a 120 VAC electric element, the two temperature controls for it are on the backside of the tank where the 120VAC wires are connected. The 120 VAC heater controls are separate from the propane controls and both can be used at the same time with one shutting off before the other. A factory installed 120 VAC electric element is screwed into a 1 inch NPT hole in the back side of the tank. This 1 inch NPT hole is not present in propane only tanks.

Re: Hot water heater

Reply #21 – March 03, 2018, 01:44:32 pm

Wyatt, We found that our 2-way Gas & Electric Atwood installed several years ago had a different style circuit board that managed both the gas valve and 120-volt heating element. The two round temp sensors (thermostat & high-temp safety) were separately directly connected to board. The gas valve has its own direct wire from the board and was not powered through the two temp sensors. The 120-volt element is turned on via a dedicated 12-volt relay mounted on rear. Two separate external switches are directly connected to the board to tell the heater to turn on gas and/or electric when the thermostat calls for heat. Both gas & electric are controlled by the same thermostat, turning both on & off at the same time.

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