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creativepart · 08-14-2017, 04:35 PM

The day after we purchased our 2017 Adventurer 37F the Atwood Hot water heater quit working on gas or electric. The selling dealer was still close by so we took it in and they replaced the thermocouple and all was well.

Now 2-weeks after we returned home from the purchase location we're out for a short 3 night trip close to home and the hot water heater is down again.

Now, I know that the thermocouple was the issue last time, so I removed it and BAM the gas heater fired up immediately.

I called Atwood and they were very helpful and baffled how this could happen twice. They also were confused why the WH didn't work on electric power even with a bad thermocouple.

They're shipping me yet another thermocouple and we'll see if it goes out yet again. If so, a new circuit board will be the next stop.

With other new RVs when stuff broke I called the dealer, made an appointment 3 to 4 weeks out and hoped they'd fix it within a reasonable period of time. But with this new coach when stuff breaks I've been calling the manufacturer of the item and so far they've all just sent me repair parts immediately. SOOOO much better than dealing with a dealer's service dept.

60sumtin · 08-14-2017, 05:03 PM

You mean when something goes wrong, they'll send you a part and you get to do the labor for the warranty repair yourself? Good deal if they pay you.

Floridakamper · 08-14-2017, 05:20 PM

Quote:

Originally Posted by 60sumtin

You mean when something goes wrong, they'll send you a part and you get to do the labor for the warranty repair yourself? Good deal if they pay you.

It's a good deal if you can avoid waiting weeks for an appointment, leave your coach with the dealer and hope they diagnois the problem, order parts and then get around to installing them.

rk911 · 08-14-2017, 05:38 PM

Quote:

Originally Posted by 60sumtin

You mean when something goes wrong, they'll send you a part and you get to do the labor for the warranty repair yourself? Good deal if they pay you.

had the same issue with our atwood wh. I purchased and replaced the thermal cutoff device ($10) but now the gas heater would fire whenever I selected electric. a mobile repairman diagnosed it as a bad control board. atwood covered the part but not the labor.

to the OP...the thermal cutoff devices are designed to pop when excessive heat from the gas tube flashes back. when it does pop the WH won't work...at least ours didn't...until I bypassed and then replaced the thermal cutoff. you might check to be sure the burner tube is clean and make sure you have a nice blue flame. I also suggest keeping a spare thermal cutoff in your toolbox.

AKIQPilot · 08-14-2017, 05:50 PM

You seem to be able to diagnose and fix your motorhome as well or better than the dealer. Might be time to get a phone number for every major and minor component on the coach to have handy when needed.

creativepart · 08-15-2017, 10:17 AM

My winnie came with a list of all 3rd party suppliers and the model number of the system and it's serial number.

It makes things much easier.

And, to 60sometin, yes, it beats waiting a month to get the RV into service and then a month or more to MAYBE get it fixed.

Whatever works. That's what works best for me.

creativepart · 08-15-2017, 10:19 AM

When I bypassed the thermocouple yesterday and the LP burner started up I noticed the flame was very yellow - I need to adjust the air intake.

By the way, with the thermocouple bypassed the WH works fine on Electric. So, that's good to know.

JPO1980 · 08-15-2017, 11:19 AM

Trying to understand the problem. Could you be mixing terms? As I understand the theory of operation, the water heater should not work on LP with the thermocouple disconnected. The thermocouple's job is to hold open the gas valve when there is a good pilot light. No thermocouple or no pilot- no gas should flow.
As Atwood says, that shouldn't affect electric operation.
The thermal cutoff or ECO is a safety switch normally closed that opens when it senses an over temp condition. I wouldn't use the water heater with it bypassed.

creativepart · 08-15-2017, 11:34 AM

The "thermocouple" is what I was told the small transistor looking device in the clear plastic tube is called.

I spoke with Atwood. They explained it's function. I asked them about electric operation being effected and they said it really shouldn't be. But the thing is... it is effected.

I asked about running with the thermocouple removed. They said if you have to heat some water with propane you could do it temporarily but not regularly.

Since the WH has a male spade that the female connector on one side of the thermocouple attaches to - and the other end of the thermocouple is a a male spade, you can simply and easily remove the thermocouple and connect the wires without it.

When the thermocouple is attached. The WH doesn't operate in either gas or electric mode.

With the thermocouple removed it works in both gas and electric modes.

We've bypassed the thermocouple and are now using the WH in electric mode only.

So, this, at present, has correct the issue for us since we are at a State Park with full hookups.

Atwood is sending a new thermocouple... but suspect the circuit board might be bad. We're going to install the new thermocouple and see if things continue being a problem or not.

creativepart · 08-15-2017, 11:43 AM

Here's a photo of the thermocouple - removed from the WH:

creativepart · 08-15-2017, 11:56 AM

One more piece of info about this. When the WH has the thermocouple installed and it's not working at all there is no sound from the circuit board (when the WH is opened.)

When I first connected the wire without the thermocouple I immediately heard a small electronic sound from the exposed circuit board before the propane came on and the WH fired up. I immediately disconnected the wire and the WH again stopped working and the circuit board was silent.

After speaking to Atwood. It was decided that I should turn off the WH completely, connect the wires without the thermocouple and then turn on the electric operation ONLY to see if it would work. When I did, I immediately could hear that faint electric buzzing noise coming from the circuit board again.

So, the non-functioning thermocouple is effecting the circuit board electrically - seemingly turning it off. But bypassing the thermocouple is turning it back on again.

My guess is that it's going to turn out to be a circuit board issue in the end.

However, it's possible that when the WH failed the day after we purchased the RV and the selling dealer replaced the thermocouple that they did so with the wrong part and that is the only problem after all.

Time, and more testing, will tell.

AKIQPilot · 08-15-2017, 12:07 PM

Quote:

Originally Posted by creativepart

Here's a photo of the thermocouple - removed from the WH:

That is the thermal cutout switch. It's used to protect the water heaters electronic ignition from damage due to high temperature in the area outside of the tank but behind the door.

A thermocouple is a completely different device that is used to tell the gas valve that the pilot has gone out. On water heaters with electronic ignition a thermcouple may be used but not always. It tells the gas valve to close if the flame has been blown out by wind or something.

On an RV gas oven you must get the thermocouple hot before the pilot light will stay lit. If the pilot light goes out the thermocouple cools and the gas valve in the oven will not open if you turn the dial up on the front.

JPO1980 · 08-15-2017, 12:34 PM

I don't know who you are talking to at Atwood, but it would appear there is some confusion as to part names/functions. Agree with previous post that the pictured part is a thermal cutoff or ECO. That is why Atwood said you could disconnect to see what happens, but only for a short test.
I would not use the WH till the thermal cutoff switch is replaced.
Probably just failed and when replaced everything will be fine. However, it is also possible that the switch was doing its job and sensed an over temp condition and cut power to the WH.
Not being an alarmist, just be careful

Hikerdogs · 08-15-2017, 02:28 PM

There does seem to be some confusion in terminology. The item pictured in the OP's post is referred to as a "Thermal Cutoff" in the Atwood parts diagram. This unit is measuring heat in the cabinet around the burner, not the temperature of the tank or the water in the tank.

It breaks internally (and permanently) and shuts off power to the gas regulator when the ambient temperature in the cabinet is excessive. Atwood defines "excessive" as 190*F. Excessive heat in the cabinet is usually caused by debris, wasp nests, or spider webs in the burner tube causing the flame to burn outside the burner tube.
Here's a link to a picture of a "Thermal Cutoff"

Switch, Thermal, Cut-Off, 190 Degree F - 2 Package, All DSI Series, Water Heater - Dometic 93866 - Parts - Camping World

The ECO (Energy Cut Off) is a button type switch mounted on the rear of the heater. It is mounted in conjunction with a thermostat that normally opens and closes to keep the tank temperature at 140*F. It will open when the tank temperature exceeds 140*F. When it opens power is removed from the electric heating element. The ECO can be reset with a built in reset button.

Here's a link to an Atwood troubleshooting manual that defines the components and terminology:

Atwood Water Heater Troubleshooting

I would suspect you have a problem with the circuit board. The ECO should ONLY effect the electric heating element, and the Thermal Cut Off should ONLY effect the gas regulator. If it is having an effect on both gas and electric heating there is another problem.