Rinnai EX38C Propane Direct vent heater Intermittent code 11

rustyjack

Going into the sixth winter with my unit. Started getting code 11 intermittently (every couple of days) It's become more consistent about 50% of starting tries. The lower flame rod and igniter are new, upper one cleaned. I have removed the burner cover and compressed air blown out some dead bugs.

The problem as I see it, (and I can actually see it thru the inspection glass) is that when it will not fully start and sets code, the front lower burner tube does not light (the one that heats the lower flame rod). The back one (at the igniter) lights but not the front. After repeated attempts, usually no more than two….the front lower will light and few seconds later both upper burner tubes light and every thing works normal until the next shutdown.

I've had the burner cover off to use compressed air but am thinking the flame tracks? are not getting fully cleaned. (Maybe rust or corrosion). Problem is I see no easy way to remove the burner tubes for deeper cleaning. Any help or other thoughts will be much appreciated.

EBEBRATT-Ed

I would say you should clean it as you suspect it probably needs that done. Manual attached. I installed a similar one but never worked on it after start up. It looks pretty complicated to take apart.

I don't have a clue on disassembly other than start taking it apart. You might want to check with Rinnai first before you get in that deep to see if they have someone in your area.

The most common things would be burner cleaning, flame rods, ignitors which you have already started on. I think @Mad Dog_2 likes installing Rinnai boilers and water heaters. he may have a good contact with Rinnai. You could pM him.

200000064-RHFE-1005FTA(EX38C) Installation and Operation Manual.pdf

EBEBRATT-Ed