I noticed that the house temp was 8 degrees below what the thermostat
was set for. It has been a frigid spell here for the past days, so the
boiler has been running a lot lately. I went to the cellar and there
seemed to maybe be the slight scent of something unusual in the air.
The water level was good. I hit the reset button on the boiler and it
started right up. The burner then ran okay for 90 minutes while it
heated up the house to the temp on the thermostat.
At that point, as a test I bumped up the thermostat and the burner
turned on as normal.
What could account for the burner not turning on like that? Thanks.