2018 303RLS Water Heater Circuit Board

[Steve Kassel]

Water heater works in electric, but not in gas mode. Can't get DCvoltage to ignitor circuit. Does this point to a bad circuit board? Could it be anything else?..........Steve

[TucsonJim]

Hi Steve! Welcome.

Is it a Suburban or Atwood (Dometic) water heater?

Jim

[colan]

Would you mind clarifying what is meant by DC voltage to
igniter circuit?

A couple of suggestions:

First I’m assuming this is a Dometic water heater.

With the water heater not up to temperature, remove the igniter wire from the control board. With a pair of insulated pliers hold the lead close to the post on the control board, have someone else turn on the gas side of the water heater. Do you see sparks from the control board to the lead? If yes then the board is trying to ignite - at this point it will take more in-depth troubleshooting, though guessing and guessing is the keyword the gas valve isn’t opening or there is a kinked hose someplace.

Another quick check, remove the retaining screws for the control board. Is there a barely noticeable melted spot on the back of the board? If yes, most likely the board is bad. Not all bad boards have a melted spot. And I’ve never seen a good board with a melted spot - though I don’t run around pulling boards on correctly operating water heaters looking for a melted spot.

If the water heater is a Suburban the check for sparks process is a little different as the control board isn’t out in the open. Start with looking for sparks in the burner area while someone else turns the gas side on.

[Steve Kassel]

6 gal Atwood. Gas valve is operating. No spark from board to lead. No noticable bad spots either side of board.

[Yattr]

Had the identical issue with mine this summer and replaced it with this circuit board

https://smile.amazon.com/Dinosaur-El.../dp/B0130Y8I1K

[ncitro]

6 gal Atwood. Gas valve is operating. No spark from board to lead. No noticable bad spots either side of board.

I had this problem on my Atwood as well as my father in laws. Both were bad boards, which seem to have a reputation for going bad. I replaced both with a Dinosaur brand board, I had used them on my fridge in my old rig and had good luck. Time will tell if it is any better than the stock board.

[howson]

6 gal Atwood. Gas valve is operating. No spark from board to lead. No noticable bad spots either side of board.

Steve,
I moved this thread to the "Plumbing" section as I think we've diagnosed your issue. Check out this thread as it may be helpful: https://gdrvowners.com/forum/operati...rd-replacement

Howard