Carrier WeatherMaker with Code 31

[dgp]

My Carrier WeatherMaker 9200 stopped heating with a code 31.  From reading the forum and manuals it looks like it could be one of several things.

 

• Blocked drainage
• Blocked air duct
• Pressure Switch Failure
• Inducer Motor

The motor spins when the system attempts to fire up.  I never see a glow in the burner view port.  I have been unable to locate the inlet from the manual which shows where to pour antifreeze went winterizing.  I read that you could pour water through to see if the drain is clogged.

 

When this first happened, it was off for a day, then came back on by itself.  For that reason, I was led to believe it was the drainage.  Perhaps the Pressure Switch is getting flaky.  Is there a way to test the switch?  Or should I simply replace it and work from there?

 

dgp

[RegUS_PatOff]

http://appliantology.org/files/file/1368-carrier-furnace-operating-installation-manual/

Carrier Furnace Operating / Installation Manual
Weather-Maker
WeatherMaker Infinity
9200
58MCA
58MVP
58MXA

om58-67.pdf

(after upload approval by the Samurai)

 

31 Pressure Switch Not Closed
Check to make sure that all PVC pipes leading into the combustion-air intake and vent/exhaust

are free from any cracks and sags.

Also check the combustion-air intake and vent/exhaust pipes on the outside of your home for blockage.

> bird's nest during the summer ?

[Cactus Bob]

pressure switch failure , IS REALLY COMMON  !

 

start there !

[jumptrout]

The draft inducer motor running is normal on a call for heat.

Remove the pressure switch tubing from the draft vent.

Suck on the tubing to listen for a click in the pressure switch.

Use your meter set for continuity and test the PS terminals.

If it clicks and they close OK,replace the tubing on the DI vent.\Remove the tubing and blow through to clear any restriction at the DI vent.

Replace the tube on the PS and start yor furnace while checking voltage at the board from the PS.

[dgp]

 

From the photo, do I use the top tubing on bottom tubing?

 

And this is the pressure switch, correct?

 

Thanks to all three,

dgp

Edited November 10, 2013 by dgp

[Budget Appliance Repair]

That is the pressure switch, the lower hose is the one that supplies vacuum to the pressure switch.

 

Remove the lower hose and try to blow back thru it, most likely you will not be able to blow thru it.

 

I had one that had that exact same draft inducer motor a year or two ago and the bottom of the drafter inducer chamber will completely plugged up with rusty muck.  You may have to remove the draft inducer motor to get it fully cleaned out, also make sure the condensate drain hose at the very bottom, (the larger hose), is clear and not plugged.

 

If the condensate drain isn't draining good it will back up and plug off the vacuum hose.

[dgp]

I checked the vents and they appeared to be clear.  I then took off the top tube to the combustion chamber and (ooops) sucked through it.  I got a throat peppering of debris.  The furnace started because the tube was off.  I then reconnected the tubing and the furnace kept running.  Did I need to cycle the power after restarting?  If not, I believe the problem was blockage in the tubing.

 

Thanks all,

dgp

[Bullstok]

Edit: never mind. It was posted before about the flues and i missed it

Edited November 12, 2013 by Bullstok