Trane PTHC-090 - On Board Diagnostics; Self Diagnostic Mode

39
PTEC-M-1A
Control Board
Characteristics and
Diagnostics
• On Board Diagnostics -The LED
light will flash once every 6
seconds. If an error occurs the LED
will flash from 2 to 8 flashes every
6 seconds. Refer to the chart below
for possible causes for the flash
codes.
Flashes Situation Corrective Action
1 Flash Control Ok Board OK
2 Flashes 24vac Fuse Blown Replace fuse
3 Flashes Indoor Coil Thermistor failure Replace Indoor Coil Thermistor
4 Flashes Mode Switch Failure Replace Board
5 Flashes Thermostat Control Replace Board
6 Flashes Bad Thermostat Input Failure Replace Board
8 Flashes Indoor Ambient Thermistor Failure Replace Thermistor
• Self diagnostic Mode - The
diagnostic mode is initiated by the
following routine. Set the
thermostat in the coolest position
and the mode switch in the off
position. Rotate the thermostat
counterclockwise to the warmest
setting and rotate the mode switch
counterclockwise to the fan only
position simultaneously and wait
two seconds (or until fan relay
engages). Return the thermostat
and mode switch to their starting
positions by rotating them both
clockwise simultaneously. The
diagnostic routine will run the unit
through each mode in the
following sequence:
Mode Time
Fan Only 17
Off 1
High Cool 17
Off 3
(reversing valve energize)
High Heat
(rev cycle) 17
Off 1
Low Heat
(elec heat) 5