Have it replaced. Dealer won't have any parts nor knowledge to work on it. It is to easy to pull it out and put in another one.
I just pulled mine out today to cut a hole for a vent in order to get air into the cabinet so the darned thing can breathe. Intake for air into the heater is in the cabinet and it can only draw air from holes left during construction (underbelly) etc.
Fireplace is just an electric heater with a display plugged in to an ac outlet in the cabinet, so, dealer can replace it PDQ.
Charles & Martha Myatt
2009 Duramax w/Transfer Flow Fuel Tank
2016 Flagstaff V-Lite 30WFKSS
Almost South of the Border