Furnace Cycling - SOLUTION w/ Pictures
EDIT: This turned out to be an air flow issue. The solution was quite simple. The furnace has three knockouts on the back when using flexible vent duct adapted to hard in-floor ducting. Crossroads has...
Forum Discussion
wanderingbob wrote:
This is May , you do not need any furnace !!
It was hovering around 10 degrees C Friday night...If it were just me and the wife we could have generated our own heat ;-). The baby boy and 4 and 7 year olds were complaining about the cold...
five'er wrote:
I recently tore my furnace apart (every piece) sorry to say but it's pretty much required to get to anything.. blower would start, It would spark but not ignite three times then shut down. I knew at that moment it was either orifice or bad valve. I cleaned it all up (Full of fine rust) and re-assembled and it fired right up, better than new. Based on your problem description I have the following thoughts.. It's an intimidating task but when you're cold.. you do what you need to do.
Blower is coming on and there is ignition.. I assume you can hear the fires burning.. I don't believe (I may be wrong) that it will light unless it's passed the sail switch stage (Which is located inside the blower/fan assembly on mine). So I'm saying sail switch is out.. High limit switch.. I'm not sure.. I'd say not likely.. My educated guess.. flame sensor? I believe the flame sensor is also the igniter. Clean it with some sand paper if it's not working correctly.. The other thing to check first would be that nothing has obstructed your in and outtakes.. Again, a semi-educated guess.. The other thing you can and should do is reseat the connection on the control board. OR.. Just wait for the service guy..
Yep, I can hear it running. It doesn't appear (based solely on air flow from vents/exhaust) that anything is restricted. And while it's blowing, the air coming out is nice and warm like you'd expect. Just that the burner cycles while in operation.
downtheroad wrote:
I agree with Skip above
Close the bathroom door.
Or like you said, "Maybe the one in the bathroom is heating up the paper-thin wall between the bathroom and thermostat and triggering it that way."
You can isolate the thermostat.
It can't be the sail switch if the furnace ignites at all.
I'll take a closer look when we head out on the weekend. Forecast is for warm weather now though, so testing this out will be a real pain! Have to crank it up to 30 to test.
Thank you everyone for the ideas. If I still have trouble I'll get the service guy involved for sure.
