[bpp]

I recently had the inducer motor replaced when it burnt out but I am having issues again. The inducer motor keeps running and won't stop until the whole system shuts down.

Let me correct myself. I actually am reading about 26 V on the terminals of the pressure switch. The voltage on the pressure switch and high limit switch is 26V for most of the time but at some point I watched it race up to 50V and then I think the switch cutoff. Also, I assume the inducer motor should shutoff at some point in the heat cycle (so lets say a min or so) instead of being on for 10 minutes and then shutting down with the rest of the system. It shuts off before reaching the set temperature.

I am also getting some error codes but it seems to be different every single time. When the burners shut off I have gotten a code for
-normally open pressure switch contact did not close at the beginning of the heat cycle
-primary or auxiliary switch has opened its normally closed contacts

Then after it shutsdown I have gotten the following errors:
-pressure switch opened 4 time during the call for heat

I think it might be a problem with the condensate drain but have had no luck fixing it. There is a place just above where three condesation lines meetup in some plastic piece and then into a drain pipe out of the furnace. Inside this plastic piece, the center input doesn't drain like the other input lines but I am not sure if this is a problem or that is design (I can't take the piece apart). Either way I have tried to clear all the passages using my shop vac but still no luck.

My other guesses is it would be either the control board or the pressure switch needs to be changed. Any help would be greatly appreciated.

[hvac1000]

Disconnect the pressure switch making where the wires went. Use a meter and activate the pressure switch by blowing on the small tube. The meter should register different during this action. This will test the pressure switch. It is possible when the other inducer motor burnt out it damaged the circuit board also. I guess the furnace is running correctly other than this problem?

[bpp]

Disconnect the pressure switch making where the wires went. Use a meter and activate the pressure switch by blowing on the small tube. The meter should register different during this action. This will test the pressure switch. It is possible when the other inducer motor burnt out it damaged the circuit board also. I guess the furnace is running correctly other than this problem?

With the unit off, I unplugged the wires and the tube and blew into it. I assume I am measuring for a change in resistance when I blow into? I am guessing the air pressure completes the contacts and I should measure continuity when I blow into it?

[deestop]

Don't blow... gently suck in on it, you may damge the diaphram inside... 99 percent of time the switch isn't bad , there is an obstruction of some kind.The pressure switch is just doing it's job.. I have seen from birds in intake or exhaust lines to heat exchangers bad causing this problem. Unturn every stone and do not get fixated on one cause

[deestop]

Did you here a click at gasvalve and hear gas flowing for 2 seconds or so? If so all systems go.. you have bad igniter