Carrier 58MSA - Error code 31 - blower starts but main blower never does
#1
04-13-12, 08:50 AM
Carrier 58MSA - Error code 31 - blower starts but main blower never does
I'm calling for heat. light is steady on. the blower starts and runs for about 30 seconds before it generates an error code 31. The main blower never comes on. I have assured all vents are clear. It all looks clean and sounds good. No evidence of leaking water. Any suggestions?
#3
04-14-12, 01:01 AM
Member
Code 31 on your model indicates that the pressure switch isn't closing.
The pressure switch makes sure that there's a proper draft (created by the inducer/venter motor) prior to ignition.
Check the exhaust and intake pipes for a blockage where they exit the house.
Make sure that the condensate drain isn't blocked.
With the venter motor running, wave your hand over the end of the exhaust pipe - there should be air movement.
Other problems can cause the pressure switch not to close; call a technician if it's not something obvious.
The pressure switch makes sure that there's a proper draft (created by the inducer/venter motor) prior to ignition.
Check the exhaust and intake pipes for a blockage where they exit the house.
Make sure that the condensate drain isn't blocked.
With the venter motor running, wave your hand over the end of the exhaust pipe - there should be air movement.
Other problems can cause the pressure switch not to close; call a technician if it's not something obvious.
#4
04-14-12, 07:37 AM
Blower voltage 225vac
Yes, the trap is clear, and there is free airflow in and out of the venter blower. I checked the blower voltage and it is 225vac. It seems/sounds pretty normal with strong airflow. It just comes on and after about 20-30 seconds the light starts blinking the 31 code... is it time to call in a pro? I'd love to win this one 
#5
04-14-12, 07:22 PM
Member
Is 225vac a type-o? Furnaces are normally 120 volts.
Check to see if the pressure switch is actually not closing. (with a meter)
You can also make sure that the tubes connected to the pressure switch are clear.
It's possible, but unlikely that the switch itself is bad.
If everything seems okay, call a pro.
A heat exchanger with popped crimp rings or large cracks can prevent the pressure switch from closing.
Check to see if the pressure switch is actually not closing. (with a meter)
You can also make sure that the tubes connected to the pressure switch are clear.
It's possible, but unlikely that the switch itself is bad.
If everything seems okay, call a pro.
A heat exchanger with popped crimp rings or large cracks can prevent the pressure switch from closing.
#6
04-17-12, 06:28 PM
Tubes must have been clogged
Sorry, that was a typo. The voltage is 125. I "tweaked" the tubes by pinching them and rolling them the full length. I tapped the pressure switch with a screw driver. It now works fine. How long it works is anybody's guess, but at least I know how to tackle it next time. Thanks for all the help, and saving me $. 
