Perplexing furnace issues

[jhawkwest]

Once again, last night, the furnace in our Precept refused to work. We woke up and it was 48 degrees inside. Brrrr. This has happened a few times, even after some dealer attention and a replacement of the furnace circuit board.

Previous issues: thermostat triggers the furnace, furnace fan comes on, failure to ignite. Solution - replace circuit board. Furnace works fine.

Another trip: furnace is working fine but suddenly won’t ignite. Full gas flow to the refrigerator, stove, water heater - all those systems are happy but no heat. In to the dealer. Everything works just fine.

Another trip: oops, same thing. Sherlock Holmes that I am, I figure it’s the igniter since the thermo activates, the pre-light sequence starts, the board was replaced, the ignition is clicking but no gas ignition. In to the dealer. Everything works perfectly and we still have a gas flow to all other appliances. Some bad language used.

This trip. Furnace is magic for two days - never misses a beat. 6 AM, gotta pee. 48 degrees. DAMN!. Now, the thermo turns the AC fan on just fine but I don’t need AC - it’s 48 degrees. Switch to heat, thermo clicks. Nothing! No pre light sequence, no discernible heartbeat, nothing! Shivering. Check the furnace circuit - ok of course. Getting cold and desperate. Throw all the breakers. Throw the power shut off. Too cold and it’s too early for a beer.

Help. 💩