HW heater on the fritz

[Rayco]

This forum has been extremely helpful to me as a new fifth wheel owner. You can see our equipment below.

We are on an extended trip and a few weeks ago the hot water heater stopped working on electric. Since then it's been working fine on gas - until yesterday. Now it's not working on either electric or gas. I've checked the breakers and fuses (although I know there are more hidden somewhere) and they all are fine.

On gas, I don't see any ignition spark. I can manually light it, but it seems the thermo couple doesn't recognize the heat and it stops the gas after a few seconds.

Any ideas on what to check??

Thanks in advance!

[Rustic Eagle]

Suburban or Atwood hot water heater?

Bob

[Rayco]

if the sheaf of literature in the Jayco bag is correct, it's a Dometic

[Rayco]

... with spark ignition

[RogerR]

I suspect an electrical fault somewhere. But I have no experience.

I do suggest you inspect the back of the fridge for plugged vents, plugged burner assembly, or any int eruption of the flow of air over the coils.

[Shackrat]

Originally Posted by Rayco

if the sheaf of literature in the Jayco bag is correct, it's a Dometic

That means it's an Atwood.

If the electric element isn't working, and the gas burner isn't lighting, that points to the control board. Is the DSI fault LED lit? If it is, it may be the thermocouple.

If it's not, the control board may not be getting power, it may have failed, or perhaps there is wiring damage between the control switches and the water heater.

You need a multimeter to do this, but I highly recommend measuring the low-voltage connections to the WH control board to make sure 12v is getting to it and to make sure that the gas/electric switch connections have voltage when turned on too.

[RipinSC]

Sounds like the famous circuit board. Call Jayco or Dometic direct. Most all dealers have them in stock as they fail on a regular basis.

[TCNashville]

If the unit is going through the motions it needs to light, I suspect its a bad flame sensor [ignitor].

[Dogrunr]

Just got my rig out of the shop for HW not working in both electric and LP modes. RV Tech said they had to replace the control/circuit board of the Atwood HW heater. Note: The Tech also replaced my Progressive band "All in One" 50 Amp power control/fuse panel. He indicated that Atwood water heater control boards are sensitive to high voltage and my power control unit was showing weird power fluctuations on his volt meter. Glad I had a zero deductible extended warranty.

[Rayco]

Ultimately the dealer had to replace the circuit board on our water heater.

Recently, I noticed it works fine on electric, but when I switched to gas it ran and ran and ran....... So I went outside and opened the panel to find water trickling out of the blow-off. Does anyone know if the temperature sensor to turn off the heat source is the same for electric and gas, or are there 2 different sensors?

[TCNashville]

Sounds like your thermostats have failed. Here is an older video showing you where they are. You might try just jiggling the wires.

https://www.youtube.com/watch?v=uYzqP2BFrMk