Error 101: Y1 Relay Fault; Error 104: Heater Relay Fault - Trane ACONT900AC43UA Service Manual

Error 93: Gas valve fault
Comfort Control = Err 93
User Interface = INT GV ERR
Furnace Fault LED = Solid ON
Problem Description
• Control board sensing voltage when voltage should
not be present
Possible Causes/Solutions
• Replace furnace control board

Error 101: Y1 relay fault

Comfort Control = Err 101
User Interface = Y1 OFF ERR
Air Handler Fault LED = 7 Flash
or
Furnace Fault LED = No Fault Reported
Problem Description
• Y1 relay on indoor unit control board is "OFF" with a
call for cooling
- If comfort control is setup for single stage cooling
and a communicating outdoor unit is not discovered
on the communicating bus, the Y1 relay on the indoor
control board will apply 24v to Y1 terminal on a active
call for cooling
Possible Causes/Solutions
• Internal control failure
• Replace control board
Alert Code Response
Error 101: Y1 relay fault
Comfort Control = Err 101
User Interface = Y1 ON ERR
Air Handler Fault LED = 7 Flash
or
Furnace Fault LED = No Fault Reported
Problem Description
• Y1 relay on indoor unit control board is "ON" without a
call for cooling
- If comfort control is setup for single stage cooling
and a communicating outdoor unit is not discovered
on the communicating bus, the Y1 relay on the indoor
control board will apply 24v to Y1 terminal on a active
call for cooling
Possible Causes/Solutions
• 24 volts sensed on Y1 terminal of low voltage terminal
board without an active call for cooling
• 24 volts applied to Y1 terminal when a
communicating outdoor unit is installed
• Onboard Y1 relay stuck closed
- Replace control board

Error 104: Heater relay fault

Comfort Control = Err 104
User Interface = HT OFF ERR
Air Handler Fault LED = 4 Flash
Problem Description
• Heat relay on indoor unit control board is stuck open
- The heat relay provides a 24volt input to each bank
of electric heat when a call for auxiliary heat is present
Possible Causes/Solutions
• Replace control board
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