This has occurred after sitting overnight. Heater attempts to light( fan runs, ignitor operates) but then blows out 1-3 puffs of smoke and then shuts off. Repeated attempts to start the heater yields same result. This has occurred after running normally all day the previous day. I have replaced all filters(including fuel), the HSA ignitor, and cleaned the photo cell lens. Am wondering what I should try next? Heater is operating in somewhat dirty(sawdust) environment.
csillman

Your pump pressure may be low.

On the back of the pump there is a small raised nipple with an adjustment screw. The screw has a small hole in the screw.
Put your thumb over this screw hole and see if the unit will start at that point.

Also check the back square black cover of the pump to make sure there are no cracks in the cover.

Hello I'm new here.. and rather new to the DESA heater products, BUT...
their engneers think like I do... I guess that is why im very impressed with the products.. back to your problem at hand... the pump pressure is the problem.

now you say you operate in a dusty area, so i would start with fuel filter, next check the psi output of the air pump, if this is ok then check the nozzle for obstrustion, you can blow it out with compress air, ( please remove the nozzle from the holder ) with the nozzle out check the O ring on the nozzel,if chipped or comming apart, replace it, ya know it takes longer to type this than to do the work... the DESA line is very simple and a pleasure to service, I sad to see them gone...

I can repair ignition boards 104068-02...ECT.

What do you charge to repair a circuit board.

Do you have refurbished boards?