A pressure switch error on a trane furnace may lead to a very cold home if not corrected in a timely manner.
Trane gas furnace pressure switch error.
1 a restricted vent pipe 2 too long of vent piping and too many turns which exceeds manufacturer s recommendations 3 a stopped up condensate drain line if you have a high efficiency condensing furnace.
4 a dirty or stopped up draft inducer.
Let me clarify the bottom side of the pressure switch is the intake that has a small white flexible hose attached to it that runs down into air intake area.
It should be clear.
There s a motor engaging but after 5 speed ups the system disengages with the 3 flash error code for the inducer fan or pressure switch.
Then three service calls a limit sensor a pressure switch a blower motor.
Inspect the hose s connected to the pressure switch to make sure it is connected at both ends and is in good condition.
The exhaust side of the pressure switch actually splits into two hoses.
If the hose is cracked replace it.
Vent pressure error three flashes on the trane furnace control board means that the vent pressure is too high or too low which then activates the pressure switch and causes a lockout.
Remove the main access panel on the front of the furnace.
When a pressure switch error occurs the system will shut down and no warm air will enter the home.
This error code remains flashing through the next cycle until the moment that the furnace should activate then disengages and errors out again.
The pressure switch is an indicator of pressure problems in the furnace.
And about 400 later the problem still existed.
Inspect the pressure switch hose.
The sensor closes when the furnace kicks in and allows heat to enter into the home.
One potential error is a furnace lockout which is not something that every furnace user knows about.
One goes to the gas valve and the other one goes to the bottom of the furnace where the burners are.
Check the tubing from the inducer.
A pressure switch senses pressure within the flue system.
Also the fittings that the tubing fit into should be clear.
Some other things that cause furnace pressure switch problems are.
Other problems that could cause the pressure switch to not open are a dirty blower wheel on the inducer.
