Atwood 8535 heater

[prento]

Hi all,Attwood 8535-iv dclp heater problem on my rv,the heater will start up(fan going)but is having trouble lighting the furness sometimes it lights then it cuts out and stops,if you look at the circuit board outside next to the heater there is a red warning light on the circuit board that flashes 3 times off and on,any ideas what the problem is.

[Gary RVRoamer]

#-flash code means Ignition Lockout, i.e. it tried to light multiple times but failed each time. Lockout means it quit trying.


WHY it didn't light is for you to figure out, but odds are it has to do with air intake and/or exhaust outlet air flow. LP furnaces are very sensitive to the air/fuel ratio and a bit of rust flakes or insect nests in the intake & exhaust tubes can disrupt the flow enough that it won't light.