About a year ago, November of 2021 in Canada, our furnace started acting up. It would run normally, but then intermittently would not start up again when the thermostat was asking for heat. Needless to say a major issue when it is -10c (14F) outside.
I discovered that if I took the cover off the front of the unit (outside), and just touched the squirrel cage (blower), it would start up again. This was happening quite regularly so we had no choice but too move out. Normally, we travel South, but due to Covid, we found elsewhere to stay. Actually the year before, we spent the entire Winter in our FL36, quite an experience but I am getting off topic.
In April, of this year, I purchased a new furnace, installed it, and now in November (again), we are experiencing issues with the replacement furnace. Several times, the furnace starts, and shuts down. So yesterday was diagnostic time, so I checked the following:
-No problem with propane.
-No problem with thermostat, 12V at the furnace from the thermostat when it's calling for heat.
-12 volts at the furnace.
-Sail switch is activated when the blower runs, and there is 12 volts on either side of the switch.
Having said that, my original furnace exhibited similar issues a few years after purchase. We were heading South so we stopped at a repair shop, since we were still covered under insurance. The technician 'played around' in there and the furnace started and he could not find any issues. We went to camp overnight at a nearby trailer park, and the furnace stopped again through the night. We called the repair shop (which was nearby) and they returned to take another look. At that point they decided to change the control board, which solved the problem. It would appear that the circuit board had overheated in some areas.
So with my limited experience at repairing these furnaces, I have come to the conclusion that the control board, in my less than 1 year old furnace, may be defective.
I am especially concerned about trying to pull out the circuit card of that unit without having to pull the entire furnace out. My original furnace had a mounting bracket for the circuit card with 2 screws on the blower housing with no issues with accessibility. This furnace does not have that bracket, I suppose cost saving measures. The card seems to be snapped into the side of the blower in an unaccessible location.
If you had the patience to read through this and any of you have any experience with these furnaces, then any further insight would be appreciated.
2021 GM Denali HD 3500 Dually Diesel 4x4