The next thing i checked was the main blower motor which was working fine when i by passed the control board and powered the motor directly. The pressure switch should be open when the unit is not running when it calls for heat the inducer should start and close that switch tap the switch and take the hose off make sure its clear.
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Ducane furnace pressure switch open with inducer on. I put in a ducane furnace last winter and last year it worked great. Hello this is my first post on here so any help would be great. Not on hand that will not function. What the unit is doing is the inducer motor will turn on the pressure closes i have my meter testing it at this point and then the igniter starts to glow and. Ducane furnace light flashes three times pressure valve open with inducer on i have a two month old never used ducane gas furnace model no. If the pressure switch is stuck it does not send enough power to the inducer and therefore the ignition sequence does not begin.
I certainly did not trip that switch. F your vent piping is open the hole in your draft inducer is open not clogged with debris or water and your pressure switch is working properly then pressure switch will close the connection between two wires and send a signal to the control board. It means the furnace thinks the pressure switch is open with inducer on. A furnace pressure switch is a safety device located near the draft inducer motor of a gas forced air furnace. The error light flashes 3 times after attempted start up which indicates per the manual pressure valve open with inducer on. What youll need a gas furnace pressure switch closes to allow current to pass through and start the ignition of the furnace.
I then tested the heat terminal on the control board and after the burners lit i waited for approximately 40 seconds plus to see if i had 110 voltsno reading. When it is not running i have 12vac across it. Ask your own hvac question i have 12vac across the switch when it is running. The switch is there to prevent the furnace from running unless the correct venting air pressure is present. After about a minute the main blower motor fails to start and the unit shuts down. After replacing the pressure switch the furnace ignitor will glow and the burners will kick on.
The issue could be a broken pressure switch due to a clogged flue. I then pulled. I have tested everything the venting is correct i blew out the hoses i tested the pressure switch. Continue reading below our video of the day. This year it keeps tripping and the flash code says inducer motor on and pressure switch open. This could be a pressure switch limit roll out switch or furnace control board problem.