Gas side of water heater blowing 2 amp fuse

[Dirtydirt]

I have replaced the relay on the back of the water heater (GCH10A-4E Atwood). Replaced control board, cleaned ground locations, tested safety link on t-stat terminal, inspected igniter on burner, each of these check out but continues to blow 2 amp fuse each time I try to light the gas burner. The electric side is working fine. What can I test to fine the overload on that 2 amp fuse????

[DavidM]

I am surprised that it is just a 2 amp fuse. That would be enough to power the controls, but you also have the flame ignitor and more importantly the solenoid valve controlling the propane to the burner. Those could very well add up to more than 2 amps.

So check the spec on that fuse and maybe replace it with a 5 amp and see what happens. 5 amps should be low enough to protect the wiring.

David

[Dirtydirt]

Thanks for the advice. The 2 amp fuse has been in form new so I don't think I should up the amperage. A friend told me how to test the solenoid so I think that will be my first step tomorrow. Thanks again

[creativepart]

Call Atwood tech support. They are pretty good at diagnosing stuff like this over the phone. And good at sending out parts to fix issues, too.

[Morich]

Originally Posted by Dirtydirt

Thanks for the advice. The 2 amp fuse has been in form new so I don't think I should up the amperage. A friend told me how to test the solenoid so I think that will be my first step tomorrow. Thanks again

Definite good thinking here. Changing a fuse based on the little we know of board design is one way to have to replace the board! Fuses on boards are often smaller as the current on the board is low.

[creativepart]

It's a fairly well known fact that the Atwood control board has a 2 amp fuse. Especially since that control board has been a problematic part over the years.

It's also not an issue you see reported much (ever) of that fuse blowing. Something is wrong and shorting for this to happen.

You already replaced the control board and check a lot of other stuff. There is a thermocouple that senses the presence of the flame once it ignites. Since you blow the fuse when you light the gas burner might that be a possibility?

https://www.amazon.com/Atwood-Mobile.../dp/B0007XS06Q

[Dirtydirt]

Thanks to all who replied. I found my problem. The spring came out of one of the thermostat buttons and touched the 12 volt terminal and caused a dead short.
The way I found this is, I made up a jumper including a 5amp fuse to entergize the gas solenoid alone. The solenoid worked fine, then I connected the solenoid to the stat. And touched the other side of the stat and the 5amp inline fuse blew. Note I disconnected all wires to the control board and run a separate ground direct from the battery where I connected to 12volt. I hope this can help others, Glenn

[DavidM]

Originally Posted by Dirtydirt

Thanks to all who replied. I found my problem. The spring came out of one of the thermostat buttons and touched the 12 volt terminal and caused a dead short.
The way I found this is, I made up a jumper including a 5amp fuse to entergize the gas solenoid alone. The solenoid worked fine, then I connected the solenoid to the stat. And touched the other side of the stat and the 5amp inline fuse blew. Note I disconnected all wires to the control board and run a separate ground direct from the battery where I connected to 12volt. I hope this can help others, Glenn

Great diagnostic job!!! Much better to do some clever diagnostic tests rather than start replacing parts.

David