# Hot Water Heater Won't Turn Off



## Oregon_Camper

Flipped on the HWH and went off and did all my other setup routine. Finished all those...unloaded dirt bikes...had a cold beer...etc.

About 45 mins later I hear my HWH still burning. I know something is wrong. I checked fuses, but nothing really obvious to me is wrong. HWH said something about a thermo-coupler (??) is wired directly in line with the system.

Is this something that can easily be checked/fixed or do I need to have the Mobile RV guy come out and fix this?

Again..it is heating water fine...the flame is perfect blue flame. It just won't turn off.


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## Sluggo54

It's not the thermocouple. That critter supplies the electricity to open the main gas valve, but it does not keep it open. The thermostat keeps it open and the flame going. If that's bad and you're not comfortable with electronics, it looks like Mobile RV Guy. One other possibility - are you sure the tank was full? If it was not, the 'stat might not have been satisfied, thus the continuing burner superheating the water.

Sluggo


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## Oregon_Camper

Sluggo54 said:


> It's not the thermocouple. That critter supplies the electricity to open the main gas valve, but it does not keep it open. The thermostat keeps it open and the flame going. If that's bad and you're not comfortable with electronics, it looks like Mobile RV Guy. One other possibility - are you sure the tank was full? If it was not, the 'stat might not have been satisfied, thus the continuing burner superheating the water.
> 
> Sluggo


I'm "ok" with electronics....and given the right information, I should/might be able to fix this on my own.

As far as making sure the tank is full. How would I check that? I turn on the water pump...and it fills the hot water tank. I don't have the bypass lever flipped (to winterize) so I think it is filling up. We did take showers, and there was plenty of hot water. I just had to manually turn off the heater each time.


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## jozway

Probably a bad t-stat. Not sure where it is and how to replace it though. Does your manual say anything about it?


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## LarryTheOutback

Oregon_Camper said:


> I'm "ok" with electronics....


I thought you were in marketing









Ed


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## Oregon_Camper

LarryTheOutback said:


> I'm "ok" with electronics....


I thought you were in marketing









Ed
[/quote]

Whew...tough crowd around here.


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## CamperAndy

The thermostat is surface mounted to the tank and is held against the tank with black insulating tape. Open the outside access and you will see two items under the tape, one is the thermostat and the other is the over heat trip. Make sure the thermostat is pressed against the tank. The thermostat can go bad and short out but I think the first fault will be lack of contact to the tank.


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## jrayburg

I just had to replace my t-stat this weekend.
The connection on the Right side had rusted out. (Not sure why)
The black insulation peels off and there are 3 metal tabs holding the t-stat firmly against the tank. I bent the tabs out and removed the small round t-stat. I reconnected the new t-stat to the wiring and replaced it. Quite easy. Good thing that's all it was.

I bet yours is just stuck on. The kit I bought was about $24 for both the left and right t-stats. I don't know why there are two different ones. One is black and one is brown. Maybe someone here knows which is which and what they do.

Johnny


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## Oregon_Camper

CamperAndy said:


> The thermostat is surface mounted to the tank and is held against the tank with black insulating tape. Open the outside access and you will see two items under the tape, one is the thermostat and the other is the over heat trip. Make sure the thermostat is pressed against the tank. The thermostat can go bad and short out but I think the first fault will be lack of contact to the tank.


Thanks Andy....

In your picture...the black tape is just below the drain...right?

Do i need new tape or will this tape restick again?


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## CamperAndy

It is right below the T & P safety valve. It should restick.


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## jrayburg

Okay,
I did replace my t-stat. I turned on both the gas and electric switches in order to use them in unison. The gas fired up and I assumed the electric did it's job.

I used the shower about 15 minutes after replacing the t-stat. All was nice and warm.

2 hours later....no hot water. I went outside after running the hot faucet for about 5 minutes. The hot water heater did not fire up the gas.

I disconnected one of the wires from the t-stat and replaced it. The unit clicked a few times and fired right up. The water got boiling hot. The unit cut off after heating the tank and no more hot water.

If the electric is not heating the tank and the gas is not coming back on to replenish the hot water....what might be the cause?

Any ideas? Do I need to replace the ECO - Electric Cut Off? Is that what it's called? The kit I bought contained both.

I knew that the "fix" was too easy. By the way...I didn't mention that the connector tabs on the new t-stat were slightly larger than the original. I had to upsize both connectors.

I was hoping to avoid paying the dealer for this repair.

Thanks in advance for yall's help.


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## CamperAndy

ECO should be Emergency Cut Off. The electric would use the same tstat as the gas.

Have you tried pulling the connector off the control board and cleaning the contacts?? It still sounds like a thermostat issue but a dirty connection will act simalarly. Last resort is to replace the control board.


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