Hotwater heater,electric yes, propane no

[PULLEY]

Last week it was the furnace, this week is the Atwood Model GCH10A-3E 10 gal. water heater. Electric works. Propane does not work. Turn remote switch on, pilot light does not come on.Turned electric switch on and works. Removed left wire to E.C.o. switch as per manual and checked to no avail. would appreciate some feedback as to possible problem. thanks. Keith

[PULLEY]

Last week it was the furnace, this week is the Atwood Model GCH10A-3E 10 gal. water heater. Electric works. Propane does not work. Turn remote switch on, pilot light does not come on.Turned electric switch on and works. Removed left wire to E.C.o. switch as per manual and checked to no avail. would appreciate some feedback as to possible problem. thanks. Keith

[glenda1908]

We had this happen in one of our coaches and it was the diode that was burnt out, therefore it would not light the pilot light. The diode acts like a safety mechanism so it burns out instead of your water heater. Just a suggestion.

[Tenn.Vol.]

Pulley, do a search on thermofuse, or just
waterheater fuse. Lots of information, as
this diode looking thing is a safety fuse.
Radio Shack has them for like .50cents each.
The end is color coded as to what temp it
will open up. And you can not solder the
fuse to the lugs. good luck!!!!!!TENN.

[Golfingene]

We just returned from a trip during which our electric water heater failed, heated great on gas. The red light glows, no heat. would this be the same diode?

[johan]

Golfingene:

There is a little story to tell provided your heater is a motor aided (With the cooling water)Atwood heater. The motor cooling water heats your water up (while driving) that high that an internal safety device trips the electric circuit.This stupid thing doesnot know where the heat comes from and you have to reset this at the back of the heater.There is a cure from Atwood. This was part of a readers question in Motorhome a while ago. If you want to read it I can send this to you because I do not know how to make an attachment to this note.

[PULLEY]

Thanks everyone for the feedback. Fore sure mine is not motor aided. I will try some of the suggestions and see what happens. Keith

[Golfingene]

johan
Thanks for solving the puzzle. It is absolutely amazing how much knowledge there is on this forum. Now to find the back of the heater...

'04 Journey 39K

[johan]

Golvingene:
If you give me your e-mail address I will send you a little write-up on this subject because I cannot find a button to fix an attachment or how to past this into zhis message.
John

[johan]

Well I finally was able to copy the following story I picked up in the Motorhome magazine. It is self explanatory:

Motorhome April 2005

Written by Wes Caughlan in Coach and Chassis

Question:

Too hot water

We own a 2003 Itasca Sun that was build on a W22 Workhorse chassis with the Atwood Electric heater which gave us some trouble. We were told that the emergency thermostat was bad. The OEM told us that it was a Winnebago issue. The Atwood heater uses the engine coolant as a means to heat the water for use in the coach. This gets so hot that the electric safety temperature limiter trips the electrical circuit and if it gets cold again does not reset unless you do this manually. But this limiter is at a very awkward position at the back of the heater.

Note :

The writer of the question said that he waits until everything gets cold and then turns on the electric heater. Well I cannot do that at all, the heater simply does not work electrically since I own the motorhome.

Lloyd Rivers/ Taylorsville / North Carolina

Answer:

You're in sort of a catch-22 situation: Atwood should have done something and Winnebago should have done something. It is a common problem that is easily solved with Atwood`s Heat Exchanger Control Valve Kit, that costs about $60. I am surprised that Atwood did not tell you about it.
The Atwood kit put a thermostatically controlled valve in the coolant hose that delivers hot engine coolant to the heat exchanger in the water heater. When the water heater reaches 140 degrees F the valve turns the coolant off and the hot water never gets too hot.
The usual complaint from owners of motorhomes with LP gas water heaters is that the pressure / temperature valve weeps and drools water down the side of the motorhome. That valve starts to open at 150 degrees F. Since motorhome coolant temperature can be well above 200 degrees F tripped electrical water heater cutouts and weeping pressure/temperature valves are considered normal by many techniciants. I consider them dangerous because an unknowing person can be scalded and permanently disfigured by water that is too hot.
While Atwood should have told you about its Heat Exchanger Control Valve Kit the that controls the temperature of motoraid-heated hot water, Winnebago should have installed the kit at the factory when it build the motorhome. At the service level we install the kit whenever we install a water heater in a motorhome that is plumbed to provide engine coolant as a source of hot water while travelling.


My heater: Type ICH6-6E Serial number 2051

[Hemi]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Last week it was the furnace, this week is the Atwood Model GCH10A-3E 10 gal. water heater. Electric works. Propane does not work. Turn remote switch on, pilot light does not come on.Turned electric switch on and works. Removed left wire to E.C.o. switch as per manual and checked to no avail. would appreciate some feedback as to possible problem. thanks. Keith </div></BLOCKQUOTE>

We have this very same problem, same atwood heater. Tonight I went out and had my wife turn on the switch while I looked for a "spark" where the gas emerges...I could not see spark...but I could hear the gas coming out..then smelled it.

Where is the diode people are speaking of ... or should I remove what looks like a circuit board coated in black stuff and just replace it?

Any other thoughts? Thanks, HEMI

[DancinCampers]

I do not have a pic, but normally it is enclosed in a clear plastic tube, and is connected from the circuit board to the thermostat. Usually close to the Pressure/Temperature relief valve.

You can remove it and connect the wire from the circuit board directly to the thermostat to see if it will lite. But don't leave it like that, as then you do not have the safety it provides.

You can also test it with an ohm meter once it is removed.

If it turns out the fuze is good you mignt check the fuze on the circuit board.

[Jeeperrmartin]

I had trouble a couple of years ago. Atwood rep at GNR told me it is usually not the circuit board. He replaced some stuff and it worked for a while. I finally took the board ino a dealer. They put it on a tester. I have had no trouble since I replaced the board.

[David K]

The thermal fuse that everyone is referring to is in the brown wire circuit that you see when you open the door to the water heater. If the thermal fuse has been "blown" the propane will not light as the electricity for the piezzo lighter is cut off. You can check this by taking the thermal fuse out of the circuit. The thermal fuse part of the circuit is normally put into the circuit with "plug in" type connectors on each end. Remove the fuse from the circuit and plug the brown wire directly into the tab where the thermal fuse was "plugged in." Go inside and turn on your heater again and see if it will ignite now. If it will, this means that the thermal fuse is bad. This is a common occurance with the Atwood heaters. The fuse it in place to protect your MH should a flash back occur that could start a fire in the heater department. As has been mentioned before, replacement thermal fuses can be bought at Radio Shack -- much cheaper than the Atwood replacements. Do not solder the new ends on as that will destroy the fuse. Also the heat that you need for the thermal fuse is 98 degrees celcius (not F).

Hope this helps. You can probably get by with running your heater once or twice without the fuse in place if you have to but, I would get it replaced instead of taking it out of the circuit permanently.

If you go up to the photo section of this forum and do a search using the words -- thermal fuse --- it will bring up one picture of the thermal fuse. This may help you in seeing it.

[Hemi]

Dave, thanks for your rapid response.

I found the thermal fuse picture.

This morning and before removing the thermal fuse I tried again to fire up the Atwood water heater in our MH...in the past (last few weeks) water heater would run (fire up with propane burning) for about a minute and then shut off. It did that again this morning and the furnance ran for about a minute and then shut off.

Next (after the furnance shut down) I removed the thermal fuse and plugged the loose wire directly into tab on the ECO. Turned on the switch on the MH panel; nothing, just the normal click that turned on the gas (I could hear it)...did it about twice and then the red light came on on the panel.

Any other suggestions? This one minute run (furnance) seems to repeat itself in the morning...we live in FL...temp is about 65-70 in the morning if that means anything.

It seems that the solenoid (gas line) is being shut off; however after it shut off this morning I did not listen closely enough to determine if the gas was still running through the nozzle--I sssume not. Further, I am assuming the gas pizzoelectric lighter either shuts off automatically when the gas fires up and thus would not turn on again if the solenoid shuts off.

There are two electrical items I see when I open the door: 1) ECO thermostat (more or less in the middle); and 2) a circuit board (black). Any suggestion on which one might be bad. Also, could the solenoid be defective...that is it would shut off after a minute or so (I don't think so). Since the shut down seems very repeatable I am guessing that the circuit board is bad...somehow the internal may have a electronic timing system that is defective. I am not knowledgeable in this area and thus this is just a guess.

At least we know the problem is not the thermal fuse.

I will wait to hear from you....I hate to take it to a service shop...cost could be considerable. I would rather replace each part one by one until the problem is solved.

HEMI

PS: One more thing; the propane in the tank is at 1/4 full....possibly I should have more gas in that tank?? However, double stage pressure regulator should take care of that problem.
Note: other items using gas such as fridge and coach furnance work fine.

[David K]

The two time try is normal on the hot water heater, then for safety reasons, it will not try again. When you switch it off and on inside the MH, that resets it for a couple of more trys. If you have a parts house nearby, I would suggest taking out the circuit board and carrying it to them to check out -- they can do this for you and would be cheaper than them coming to you. Have you cleaned out the burner tube lately -- run something through it -- I use a baby bottle bristle brush to do this and make sure that there is no blockage in the tube which would cause it to "slowly die." Since the thermal fuse seems to be OK (and I agree with your assessment based on what you wrote), I would next focus on the circuit board. I agree with you that with the other propane devices working, that it should not be a propane problem. The only other item that I can think of would be a bad thermal coupling that is not heating up right and is causing the gas supply to be slowly shut off. That would be another item that can be replaced individually -- I am not aware of any test for them but, someone else may have a way of testing them or maybe it can be tested at the same time as the circuit board.

Another quick thought, are you doing this with the water heater door closed or open ? If closed, this may be one of the famous "oxygen starvation" problems that neither Winnebago or Atwood wants to step up to the plate on. If you are trying with the door closed, try with the door open. If it lights and stays on with the door open, then you are having the oxygen starvation problem that a lot of us have. There have been numerous suggestions about how to work around this problem -- do a search on Attwood water heaters -- also thermal fuse --- water heater not staying lit. I am sure you will get a lot of hits with those searches and maybe one will fit your situation -- I am still working on getting the right one. I have "sprung" the bottom of the door, removed the insulation from the bottom of the door, cut slits in the bottom sides of the hot water heater door. Next I am going to put in vented louvers and a small computer fan that activates when the propane side calls for electricity to better circulate air.

[Hemi]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The only other item that I can think of would be a bad thermal coupling that is not heating up right and is causing the gas supply to be slowly shut off. </div></BLOCKQUOTE>

David, many thanks. This afternoon I did clean the burner system.... removed it, brushed off debris (not much, just loose rust flakes) and took a very fine wire and ran it through the brass gas nozzle...it appeared not to be plugged. Good suggestion on removing the circuit board and having it checked...I bought the RV off an consignment lot..next to a giant RV park (for snowbirds)...it has an outstanding service center but costly. I will take the circuit breaker to have it checked.

Also, not O2 starved as I have tried starting with door open.

Finally, your comment: "The only other item that I can think of would be a bad thermal coupling that is not heating up right and is causing the gas supply to be slowly shut off."

What is the thermal coupling...is it something I can see? or test or??

I also have a Bigfoot truck camper which has exactly the same Atwood water heater (but 6 gal instead of 12) which runs propane only. Tonight after dark I will have my wife turn on the switch (inside the camper)...I want to see if I can see any arc or spark in the furnace nozzle just before the propane ignites...I don't see spark or arc when I turn on the furnace on the motor home.

Again, many thanks, HEMI

[Hemi]

David

Since my post I discovered that my truck camper (Bigfoot) has almost the same Atwood water heater except that the Bigfoot Atwood heater is smaller capacity (5-6 gallon) and only has propane as an energy source.

So tonight, in fact about 5 minutes ago, I ask my wife to turn on the switch inside the Bigfoot while I looked in darkness toward the combustion chamber. After I told her to "turn on", there was a steady stream of arcing (like a spark plug) in the combustion chamber...and in a few seconds the gas burner came on. Also, there were some light emitting diodes (or similar) on the circuit board blinking very rapidly.

Now back to the motor home (2002 holiday rambler, class a): when I turn on the inside water heater switch there is no observable arcing in the gas combustion chamber like I saw in the Bigfoot water heater combustion chamber; also there is no blinking lights on the circuit board box.

Another person on irv2.com (appliance forum) suggested that I clean the spark ignition rod/heat sensing probe as carbon builds up on them...possibly hindering the arcing.

Thus for the time being I am thinking that the problem is somewhere in the spark ignition rod/heat sensing probe and the circuit board. Tomorrow I will clean the spark ignition rod and sensing probe as suggested by the other person and then I will turn on the water heater switch. As I mentioned before the thermal fuse is not the problem because I removed it and then connected the brown lead directly on the clip on the ECO. (After I figure out the problem I will reconnect the thermal fuse.)

I would not have known how a normal operating spark iginition sysem behaves if I did not have the Bigfoot camper which has the Atwood system also.

I will report again tomorrow. HEMI

[Jeeperrmartin]

If the circuit boards are the same, swap them and try it.

Like I said before I took my board to a dealer to test, and it checked bad. I think it was well over $100, but fixed it right away. I went through many of the test and things you did.

Everyone told me it is never the board. But I thought it was from day one.

[Hemi]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Jeeperrmartin </div></BLOCKQUOTE>
Jeeperrmartin

Thanks, it seems that the circuit board is probably bad...I have a few things to do before I check...such as clean the ignition probe. Many thanks, HEMI