Heat Control Board Flashing Code 3

Trane Reliatel Rooftop Units 

Re: Heat Fault Code 3

Reliatel gas/electric rooftop units have a Heat Control Board as well as the Reliatel Control Board.

There are several version of the Heat Control Board, but two main varieties: 1) Spark ignition and 2) Hot Surface ignition.

The Heat Control Board has an LED for displaying status & fault information. It is very common for the heat faults to not be shown anywhere on the Trane diagrams.

Code 3 = Pressure Switch Fault

The pressure switch should close when the inducer motor starts for a call for heat. A code 3 is generated when the switch fails to close.