Boiler sparks but won't fire

subaru400

Two days ago, this began: System calls for heat and damper opens. I can hear the gas go and the intermittent ignition spark clicking, but no ignition takes place, so system shuts down (but damper remains open). If I cut the power and restart, the damper may or may not reset, otherwise, same deal. However, both yesterday and today, it did fire up on its own (while I was of course away and unable to observe anything) and come up to temperature, but this happened on only two or possibly three cycles during the last 36 hour period, so the problem is continual but not consistent. My guesses were gas pressure issue, wiring issue or damper motor, but can't confirm why this is occurring. I did install a water heater a few weeks ago, which is why I thought maybe gas pressure problem. Any ideas? This is a 7-year-old Utica PEG Series, 225MBH, natural gas.

EBEBRATT-Ed

I would take the pilot assembly and all the burners out and clean them. Then reinstall and try it

subaru400

So far, so good - thanks, EBEBRATT-Ed