Our house power went out for a couple hours late Thursday morning. No telling what caused the power outage, the weather was fine. I assume someone either took out a power poll somewhere or a powerline transformer blew.
When the power came back on, everything but the house furnace worked OK. The house furnace had electricity and gas, but it would not turn on. We had a new Lennox furnace put in a few years ago when our old furnace from the 1960s stopped working.
I checked the thermostat and it was sending the “turn on” signal to the furnace. I noticed a single letter LED inside the control box of the furnace that was running through some kind of code, but the code made no sense to me. They did not match any of the codes that were on a troubleshooting sheet on the front of the furnace.
I called the shop that had installed the furnace and they said the earliest they could come out would be December 26 and the minimum charge would be $120. That would mean eight days with no heat. I told them I would try to find someone who could come out sooner. I eventually got in contact with a repair company that would send someone out the next day. That still meant a cold night and a very cold wake up in the morning. We live in the South SF Bay Area, but it is currently 54 F (12.2 C) outside, and the low overnight would be 34 F (1.1 C).
Even with someone coming the next day to fix the heater, I wasn’t going to freeze overnight without trying everything I could. I took another cover off the furnace and discovered that the LED readout is upside down. It was displaying the code H E228.
The manual for the furnace says Error 228 means the furnace is “Unable to perform successful pressure switch calibration.” Under “Action Required to Clear and Recover” in the manual, it said,
Retry after 300 seconds. Error counter cleared when exiting lockout, unable to perform pressure switch calibration. Check vent system and pressure switch wiring connections.
So, I kept trying to restart the furnace every 5 minutes. I did that by manually turning the furnace power off and then on using a switch that I had the furnace people install back when they put in the new furnace. Every time I turned the furnace power on, the LED told me that the controller was calibrating the furnace pressure switches, and then it would error out again with the H E288 code again. I kept at it for about an hour, when all of a sudden, the furnace came on after the calibration cycle. Hooray!
I let the furnace cycle several times on its own to make sure it was working correctly before canceling the appointment with the heater service person that was going to come the next day.
The furnace has been working correctly for several hours now. Apparently, there was a spec of dirt or something that was causing the pressure switches to not be able to calibrate. After all of my restarts, the dirt particle apparently went away and everything is working.
Newer furnaces are seemingly fussy that way. This furnace had a problem about a week after it was installed. The installers came back out and found some PVC particles from the installation that were causing trouble in a vent. They cleaned the vent out and the furnace had been working until this latest power outage.
Have you had trouble with your furnace this Winter?