Water heater mysteriously shuts itself off.

[Ray D]

My unit is a 2005 Damon Challenger, 36', Workhorse Chassis. My water heater will run from a few hours to a day or so, and then discontinue heating water. This while the switch is still on, and lit.

The first time, it ran for a day and then quit. I turned it off, figuring no point in leaving the switch on, if it doesn't work. Later, my wife wanted hot water, and having forgotten to tell her, she noticed the switch was off, and turned it on. Worked fine. Quit again, a few hours later.

I thought maybe there might be an interlock, so I turned it off, waited five minutes and turned it on, again. Worked fine, again.

Tiring of going thru the on again/off again, process, I thought of this fountain of experience and decided to see if someone here might have an idea as to why the thing kicks off, to start with. Takers?

Helpful hint, maybe. I thought maybe it was kicking off because it was too hot. Looked for a thermostat to turn it down. Didn't find it. Does it have a thermostat? Where is it? Would this cause this problem. I haven/t taken the temperature, but it is hot enough to cause a burn if not mixed with cold. It's too hot.

Help

Ray D.

 

[Ned]

I'll assume you're talking about running the hot water heater on propane, and not electric.  It's normal for the burner to shut off when the water reaches the preset thermostat temperature.  When you use the hot water, the temperature in the tank will drop and the burner will turn on again.  The tank is well insulated so if you don't use any hot water, it's possible the burner won't run for a day or more until you use some of the hot water.  It sounds like it's working correctly.

 

[Ray D]

No.

We run out of hot water, and it doesn't reheat, either on electric nor propane. I can turn on a hot water faucet, after some period of no water use, at all, and not have hot water.

I am a newby, as you know. I thought it was supposed to work on both. That is, on electric to maintain and then on propane to handle heavier usage. I may have a misconception.

When working as I expect it to work, we don't run out of hot water.  We conserve. But, I can take a shower and still have hot water when it is working as I think it should.

Ray D.

 

[John From Detroit]

There is no thermostat on the heaters Damon uses

I would suggest as a first step doing standard burner maintance.  You most likely have the very same water heater I have.

Question.  Does the FAULT lamp on the control panel come on (Red light near the heater switches) if you need to see it on to be sure I can tell you how to force it on (Unhook the red wire from the gas control solonoid, turn on heater, wait a minute and the fault light should come on, don't matter if you switch on AC or Gas, it will fault)

To reset, turn off, hook up wire and turn back on

If that light is coming on when the unit fails to operate, check your burner and ignitor as described in your owner's manual

If the light is not coming on call Damon for warranty service

 

[Ned]

The electric and propane are separate heating systems and can be used together, for rapid recovery, or separately.  We normally run on electric only unless boondocking.  Both of the heaters are thermostatically controlled, some models have separate thermostats, some use the same one.  Generally, the thermostats are not adjustable.  I would suspect the control board of failing, or the thermostat could be bad.  If the RV is still under warranty, then take it to a Damon service center for service.  Also check to see if the water heater manufacturers warranty is still in effect even if the Damon warranty is not.  In any case, replacing the control board is not an expensive repair if that's what the problem is.  Any good service facility can test the board.

 

[Ray D]

Ah Ha! The old "Read the directions," trick!

I used to be smart enough to figure that out for myself! Among the thiings that don't work so well, in my old age, is my head! I did read that manual, when we got the unit. Haven't looked at it, since. Only thing I've done, so far, is scratch my head!

There either is no FAULT light, or I haven't found it. However, when I switch the heater on, at the control panel, the switch, itself, lights up briefly and then goes off. When it discontinues heating water, it comes on again, and stays on. Depending upon how long it has been, there may still be hot water for a time, but it will run out and not reheat until I turn the switch off, wait, and turn it back on.

We just got back last night, from another 3 day trip, great time! Did the "Payette River Scenic Route," to check out driver and machine handling of tight turns and steep grades. Gained some confidence. Gas mileage went south, pretty badly, but worth it.

Have doctor's appointments for today and tomorrow. I will read the manual again, this time paying careful attention to "maintenance," and especially to the igniter and burner. May be Saturday or Sunday before I can actually get to the "take action" stage.

I appreciate the information that there is no thermostat. I was a bit put out, with myself, that I couldn't find it! Seemed like it should be a simple thing to find. I feel a bit less senile, now.

COMING ATTRACTION: I also have a lazy jack. The right rear jack goes down fine, and usually retracts just fine. However, when it gets lazy, it doesn't retract all the way.

The solution I found, so far, is to run both rear jacks back down, and try again. (Sometimes, several times.) I was going to take it in for maintenance. I will "read the directions" first, and go from there. (Unless someone has a quick fix, now.)

Ray D.

 

[Ray D]

Ned: I was writing for posting, while you were. Thanks, again.

I'm going to read the manual, again. Somehow, I got the idea that ours used electric when it was on, and then gas "on demand" when electric couldn't keep up. (Don't know whether I read that, the salesman told me that, or if maybe I made it up.) Anyway, in my initial "inspection" of the compartment, I didn't see anything that looked like an option and the only option on my control panel is ON or OFF. The tank can be seen, under the bathroom sink. The only controls, there, are bypass valves.

Will let you know how I like the book, after I read it, again.

Ray D

 

[Ned]

The light that comes on and stays on is the fault light.  When that happens, you have to reset the unit by turning it off and then on, as you did.  When that happens on gas, it can indicate any number of problems, but usually related to the burner not getting sufficient propane.  If it happens on electric, and I've not seen a heater with an electric fault light, it would probably indicate a bad thermostat or control board.  You do have a thermostat, it's just not adjustable.  If there were no thermostat, the controller would not know when to stop heating and the water would boil off.  Since it works at least once after resetting, I would have the control board checked first.

By all means, start with the manual and be sure you understand exactly how YOUR hot water heater works.  Not all are the same.

 

[Ned]

What make is the hot water heater, Suburban or Atwood?  What's the model number?  Do you have separate switches for gas and electric operation?

There won't be any controls in the HWH compartment other than the bypass valve.  Everything is controlled from the wall switch(es).

 

[Ray D]

Still? haven't had time to read the manual. However, did go out to identify the unit. It is "Atwood," 6 gal, Mod # G6A-8E. While I was there, I noticed a set of directions on the access door, inside. Not very helpful.

The door instructions refer to three different makes with instructions on how to light the pilot light. The very short Atwood instructions referred to adjusting the thermostat with a warning that setting it too high risk serious burns due to water temp. There is no thermostat adjustment, that I can find, as both of you suggested.

Examined everything in there. There is a pressure relief valve. There is nothing else that I can identify as adjustable. There are no knobs of any kind. I can see the gas valve, but it has no adjustment mechanism, visible. I can see into the burner, a ways, and it appears clean. I intend to blow it out with compressed air, if no one advises me not to. There is an "ignition detector" small short rod, that intrudes into the burner, just above the gas outlet. It is clean and appears to be in working order.

I do not have seperate switches for gas and electric. Now, I am questioning whether I have an electric element, at all.

One door instruction tells me that if the Atwood unit limits out on temperature, it will lock out until the switch is turned off, and after 30 seconds, turned back on. It says that the remote switch will light red, in that case. Also says that when the unit is turned back on, the red light will light briefly, and then go out. Guessed those parts right, except that I guessed 5 minutes - not 30 seconds. That suggests to me that the unit is locking out due to high temperature. Which, in turn, suggests to me that the thermostat is out of adjustment, with no adjustment possible. How am I doing?

Ray D

 

[Ray D]

OK, got an extra hour, and went to read the manual. (Found it, third time thru the briefcase. It was inside the furnace manual, hiding.) I see that my cooktop and furnace are, also, Atwood. I have those instruction manuals.

Also, I looked inside and out. I can find nothing that appears to be an electrical heating element. Neither can I find anything that looks like 120v wiring. I think this unit is gas, only. Where did I get the dual power idea? Beats me! (On the cover of the manual, it says "L.P. Gas, Water Heater. That helps!)

Every thing looks clean and bright in there. No bird nests, no webs, no insects, no leaves or twigs - it isn't even dusty. checked a couple of connections - bright and clean. Haven't tried blow the burn chamber out yet, but it sure looks clean. I'm not optomistic that will help, at all.

Will read the manual, as soon as possible - between appointments.

Ray D

 

[Ned]

The G6A-8E is a gas only, electric ignition, water heater.  You apparently do not have an electric element.  The described behaviour indicates either a faulty thermostat.  Try reseating all the connectors on the control board in case there is some corrosion causing it to not read the thermostat correctly.  It also sounds like your burner is fine since it does light and run, at least until it overheats.  This page (http://www.atwoodmobile.com/Service/Trouble/electric.cfm) is the troubleshooting instructions for an electronic Atwood ignition heater.  It would indicate a problem with the thermostat.

 

[Gary RV_Wizard]

Your G6A-8E Atwood water heater has a fixed temperature thermostats for gas operation. It is not customer adjustable for temperature, but it's in a semi-floating mount and changing the tightness/looseness against the tank body will alter the heat sensitivity somewhat.  If the thermostat is loose enough, it may not sense the water temperature and allow the tank to overheat (see ECO below). The thermostat is behind the wire terminals visible when the outer door is opened - there are terminals labeled ECO and TStat, if I remember correctly.

Your heater also has an Emergency Cut Off (ECO) that acts as a back-up thermostat. If the primary thermostst malfunctions and the tank overheats, the ECO shuts down the system by turning off the gas supply valve. I suspect this is what is happening to you.

The light on the remote switch should come on when you first flip the switch, indicating it is attempting to inite the propane burner. The light should go off when ignition completes successfully. The light will stay on if it fails to ignite, indicating a fault.

Your heater has electronic ignition, so it doesn't have a pilot light. It does not have an electric heating element.

 

[Ned]

We just replaced our Atwood water heater and the new controllers don't toggle the lamp when starting.? It is just a fault lamp and only lights if the burner fails or some other fault shuts the unit down.? They also now use a single thermostat and 2 low voltage switches to control the 110VAC and gas circuits, so we had to do some creative rewiring to utilize my existing 110VAC wall switch and low voltage gas switch.? Also, my new in January Dinosaur board is not usable in the new Atwood model

 

[Ray D]

Your G6A-8E Atwood water heater has a fixed temperature thermostats for gas operation. It is not customer adjustable for temperature, but it's in a semi-floating mount and changing the tightness/looseness against the tank body will alter the heat sensitivity somewhat.? If the thermostat is loose enough, it may not sense the water temperature and allow the tank to overheat (see ECO below). The thermostat is behind the wire terminals visible when the outer door is opened - there are terminals labeled ECO and TStat, if I remember correctly.

Your heater also has an Emergency Cut Off (ECO) that acts as a back-up thermostat. If the primary thermostst malfunctions and the tank overheats, the ECO shuts down the system by turning off the gas supply valve. I suspect this is what is happening to you.

The light on the remote switch should come on when you first flip the switch, indicating it is attempting to inite the propane burner. The light should go off when ignition completes successfully. The light will stay on if it fails to ignite, indicating a fault.

RV Roamer: You are dead right. Thanks.

I found the thermostat and the ECO, properly labeled on some foam tape, if very difficult to read can be called "properly labeled." They weren't exactly loose, under that tape, but they weren't exactly tight, either. I'd hate to think I "fixed" it by pushing the tape down tighter, but that's what I did. I also checked the burner. It was blue, as described in the manual. I did not adjust it. The manual sez that if the chamber is obstructed, there will be yellow in the flame. There was no yellow. With the burner on, I could see the gap in the electrode. It is supposed to be 1/8". It appeard to be correct, although I did not measure it. It did not have any cracks.

I'll have to wait for our next trip, to see how it works. If there is still a problem, I think I'll have the T-Stat replaced.

Sure appreciate the help.

Ray D

Well, I see I still don't have the quote thing figured out, yet.

 

[blackshadow43]

Hi guys how are things going? I just returned from a 3 day trip to the lake and I too am having this same problem with my hot water heater. I have the dual gas and electric heater and it seems the thermostat is not shutting off and causes my lock out light to come on. Turn it off a few sec. and it with relight and do fine till it starts to weep water out the relief valve then shuts off again. Does this on gas and electric. What should I try to see if the therm is working correctly or not?
                        Randy

 

[Gary RV_Wizard]

If it is weeping water out of the PT overflow, the first thing you want to do is to restore the air head in the tank (a volume of air above the water in the tank). After the tank cools down, disconnect city water and shut off the pump, so there is no source of water pressure. Then remove the drain plug and open the PT valve (or a hot water faucet) to drain the water, and then replace the drain plug, close the PT valve or faucet, and refill the tank using the pump or city water as the source. As the water fills the heater, a proper layer of air will be compressed in the top of the tank.

See if you still have the problem after that. You may have some additional problem, but this needs to be done first.

 

[blackshadow43]

Thanks Gary I have already done this but have not yet refilled the tank yet. I will do this in the morning and let you know the out come.

 

[blackshadow43]

Hey Gary, went out and turned the water back on and hit the switch for gas and it has never gone off yet. The water is now starting to weep again so I will be shutting it down again. I'm thinking it might be the thermostat because it seems to be getting too hot causing it to weep water. What do you think?

 

[DonTom]

Hey Gary, went out and turned the water back on and hit the switch for gas and it has never gone off yet. The water is now starting to weep again so I will be shutting it down again. I'm thinking it might be the thermostat because it seems to be getting too hot causing it to weep water. What do you think?

I think it's a good guess because something like that  happened in my old 1979 RV. The water heater thermostat would "open"  after it got up to a normal warm temperature as it should.  But then, it had to cool off to room temperature to close again.  I changed the  thermostat and that fixed the problem.

-Don- Reno, NV​