Dometic WH-6GEA Water Heater Keeps Blowing Thermal Fuses

[howson]

So if the thermal fuse opens, before replacing, I'm thinking it would make sense to temporarily jumper the thermal fuse and observe the water heater flame to see if it's burning correctly before fuse replacement?

Not a standard practice to jumper (even temporarily) a safety device, but in this case since we know the function of the thermal fuse I'd probably try to isolate why the fuse opened, too. Of course, never (ever) leave the fuse jumpered when not being actively monitored.

As a general rule, when a safety device activates I assume the event is a symptom of a problem, not the actual issue. Does that make sense?

[nomadmot]

I have also experienced this problem on my brand new Imagine 21BHE. The dealer gave me a new fuse, but the wire from the board fits very tightly and I can’t get it to go into place properly. I did check to make sure it’s the right part. Is there some trick to attaching the wire?

[howson]

I have also experienced this problem on my brand new Imagine 21BHE. The dealer gave me a new fuse, but the wire from the board fits very tightly and I can’t get it to go into place properly. I did check to make sure it’s the right part. Is there some trick to attaching the wire?

No trick, it *should* be a fairly straight-forward replacement.

[Jkwilson]

What is the purpose of the thermal cut-off? If it is a sacrificial device calibrated at 90*....it certainly has nothing to do with water temp or flame tube temp. Is it just for sensing ambient temperature for the heater control board? (electronics?) If that is the case, it is certainly mounted in a poor place.

90*C 208F much different

[Scott'n'Wendy]

90*C 208F much different

Different from what?

[Jkwilson]

Different from what?

Don’t know how I missed the quote. An old post questioned the function of the thermal cutout since 90* was much less than the thermostat set point of 140*. But the cutout is 90C.