I've tried cleaning the heat sensor, checked my connection, checked the filter, turned off gas turned back on. I'm at a loss here. I reset the furnace, left off for about thirty mins. Turned back on the blower kicked on for about 30 sec and shut off. I reset again, this time the blower came on, the ignitor lit up but the burner never through gas or ignited and it shut back off. My house is dropping into the 50s as its in the 30s outside. Any ideas on what to do? The unit is only about 2 yrs old.
My blower shuts off before the burners come on
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Sounds like a safety. The blower does run when you switch the thermostat fan switch to "on" right?
Model numbers, pictures, videos will help. You can post links after a few posts
Do you have a multimeter/amp probe?
One easy fix, if this is the prob is to clean the flame sensor rod. It'll be a 2" or so 1/8" rod connected to the main control board with a wire. With the power off, remove it carefully and clean it with a file or steel wool. Emery cloth will do in a pinch, but don't use sand paper.
Cheers!
Model numbers, pictures, videos will help. You can post links after a few posts
Do you have a multimeter/amp probe?
One easy fix, if this is the prob is to clean the flame sensor rod. It'll be a 2" or so 1/8" rod connected to the main control board with a wire. With the power off, remove it carefully and clean it with a file or steel wool. Emery cloth will do in a pinch, but don't use sand paper.
Cheers!
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17,826 Posts
Furnace model number and make?
Could be anything based on the description, carefully describe the sequence of operation.
Does the fan come on right away? after a delay?
Do you have a multi-meter, understand electrical? If not call for service.
Could be anything based on the description, carefully describe the sequence of operation.
Does the fan come on right away? after a delay?
Do you have a multi-meter, understand electrical? If not call for service.
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15,740 Posts
The first video makes it seem like the gas valve doesn't open, but the second makes it seem like the circuit board is shutting down ignition for some reason. My guess would be the pressure switch, but it could be the control board is acting weird.
Using a multimeter, check for voltage across the pressure switch after the venter motor is running. You should have around 24v (+/-3v) to ground, but close to 0v across the switch.
The other safeties (roll out, high limit, etc) should all have the same voltages as the pressure switch, except all the time during a call for heat.
W (or w1) on the control board where your thermostat wires connect should read about 24v to ground during a call for heat, uninterrupted until your house is warm.
Report back your measurements.
Cheers!
Using a multimeter, check for voltage across the pressure switch after the venter motor is running. You should have around 24v (+/-3v) to ground, but close to 0v across the switch.
The other safeties (roll out, high limit, etc) should all have the same voltages as the pressure switch, except all the time during a call for heat.
W (or w1) on the control board where your thermostat wires connect should read about 24v to ground during a call for heat, uninterrupted until your house is warm.
Report back your measurements.
Cheers!
I bought the house not even a year ago and the hvac system was just put in. Both ac and furnace have matching numbers and aren't even 2 yrs old, we'll maybe now they are. Then in summer the ac went out was told it had no freon and capacitor was bad. A company "fixed" it but it still didn't work and now the damn heat doesn't work. I'm at a loss right now on what to do. I'm borrowing a multimeter tomorrow so I'll have numbers for you then.
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42,671 Posts
The pressure switch. They do wear out.
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