Troubleshooting A Dometic Water Heater That Isn't Igniting On LP Only

Updated 10/09/2023 | Published 10/07/2023

Question:

I have a Dometic 6 gallon water heater in our 2021 Greyhawk that suddenly will not run on LP switch only. I have to turn on the electric switch plus the LP now to get the LP to light. We have always previously run this water heater on LP switch only with no issue. I checked thermal limit switch and this was not the issue. Any ideas on something else I can check? Thanks

asked by: Eric J

Expert Reply:

You'll first want to check that the board in the # DMC74FR has power and that it's running down to the T' Stat. The thermal cutoff fuse on some units sits too close the to burner tube because the were installed facing to the left so I would also recommend flipping it over to the right. From there you'll want to blow out the burner tube with some compressed air to clear out any obstructions that could prevent ignition. Since it's working with the electric switch you most likely just have debris build up in the tube.

expert reply by: Kevin C