"Pressure switch is closed when it should be open"
#1
11-21-11, 08:09 PM
Join Date: Jul 2011
Location: usa
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"Pressure switch is closed when it should be open"
My Tempstar electronic ignition furnace was recently looked at -- it was actually the first time it's been turned on in a year or so because thehouse has been vacant.
The computer was flashing a "pressure switch is closed when it should be open" error. My guy changed out the switch, cleared the flue pipe and the nipple where it connects to the fan.
Now, when I turn up the thermostat, the furnace does not start up at all; just reports the same error. Just yesterday I cleaned out the flue pipe, the tubing and connections. The pressure switch is clicking when i blow on it.
I have been able to manually start the furnace by jostling/disconnecting one of the wires attached to the pressure switch.
Any suggestions? Thanks
The computer was flashing a "pressure switch is closed when it should be open" error. My guy changed out the switch, cleared the flue pipe and the nipple where it connects to the fan.
Now, when I turn up the thermostat, the furnace does not start up at all; just reports the same error. Just yesterday I cleaned out the flue pipe, the tubing and connections. The pressure switch is clicking when i blow on it.
I have been able to manually start the furnace by jostling/disconnecting one of the wires attached to the pressure switch.
Any suggestions? Thanks
#2
11-21-11, 08:20 PM
Super Moderator
My guy changed out the switch, cleared the flue pipe and the nipple where it connects to the fan.
I have been able to manually start the furnace by jostling/disconnecting one of the wires attached to the pressure switch.
The pressure switch is clicking when i blow on it.
What is the model of the computer? And the model furnace?
Mike NJ
#4
11-23-11, 04:07 PM
you're supposed to suck on the hose going to the pressure switch to test it. Does the inducer fan motor feel hot after running for a minute or two? Can you verify with a condinuity test across the two metal points on the pressure switch while the inducer fan motor is running? Verify that it is indeed open. It might be closed, but the wires from the pressure switch might not be connected to the board, or not connected in series to the next item. this is extremely rare, but you dont hear water splashing in the inducer fan motor do you?
#5
11-24-11, 04:35 AM
the board needs to see the pressure switch open before the ID starts from a heating call from the stat....set the stat to heat then shut the service switch on the side of the furnace...pull 1 wire on the pressure switch put the service switch ON..ID comes ON then reconnect the wire onto the pressure switch.your simulating the PSI from the fan ID proofing out and closing the switch...then the ignition and then the burner...with the unit off and the wires removed are you reading open or closed on that switch
