Some other things that cause furnace pressure switch problems are.
Trane gas furnace pressure switch error.
One potential error is a furnace lockout which is not something that every furnace user knows about.
A pressure switch error on a trane furnace may lead to a very cold home if not corrected in a timely manner.
The pressure switch is an indicator of pressure problems in the furnace.
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.
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.
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.
And about 400 later the problem still existed.
Inspect the hose s connected to the pressure switch to make sure it is connected at both ends and is in good condition.
The sensor closes when the furnace kicks in and allows heat to enter into the home.
It should be clear.
Check the tubing from the inducer.
The pressure switch fitting may have a restrictor inside do not remove.
4 a dirty or stopped up draft inducer.
Inspect the pressure switch hose.
Trane xr 90 gas furnace that is coming up with three flashing led lights saying that its the pressure switch witch was replaced last spring the vents are open whats my next move read more rick.
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.
One goes to the gas valve and the other one goes to the bottom of the furnace where the burners are.
This is for anyone experiencing pressure sensor limit switch issues with the xr series trane furnaces i went the end of one winter seasons and the beginning of the next trying to resolve this issue.
Remove the main access panel on the front of the furnace.
A pressure switch senses pressure within the flue system.
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.