R - A 12
Alert Code Response
Error 93: Gas valve fault
Comfort Control = Err 93
User Interface = EXT GV ERR
Furnace Fault LED = Solid ON
Problem Description
• Control tried to energize gas valve, but 24v not sensed
Possible Causes/Solutions
• Open wiring in gas valve circuit
Error 93: Gas valve fault
Comfort Control = Err 93
User Interface = EXT GV ERR
Furnace Fault LED = 7 Flash
Problem Description
• Control senses 24v present at the gas valve when it
should not be present
Possible Causes/Solutions
• Shorted wiring in gas valve circuit external to control
board
• Incorrect wiring to gas valve
Error 91: Communication fault
Comfort Control = Err 91
User Interface = IND COMM ERR
Furnace Fault LED = 10 Flash
Problem Description
• Loss of communication between furnace control board
and draft inducer motor control board
Possible Causes/Solutions
• Faulty connection or harness between furnace control
board and draft inducer motor control board
- On a call for heat the GREEN COM LED on the
inducer motor control board should be flashing to
confirm communication with furnace control board
• Faulty inducer drive board
Error 91: Communication fault
Comfort Control = Err 91
User Interface = No Alert Displayed
Air Handler Fault LED = No Fault Reported
Problem Description
• Communication line is dead and no information has
been received
Possible Causes/Solutions
• (Air Handler only) Comfort Control Mode on user
interface is set to 24volt mode when a communicating
comfort control is controlling system operation
- Comm LED and Bit Master LED will “OFF” and 16vDC
will be measured at Data (D) line and Common (B) on
all communicating components
Error 91: Communication fault
Comfort Control = Err 91
User Interface = No Alert Displayed
Outdoor Unit Fault LED = 1 Flash
Indoor Unit Fault LED = No Fault Reported
Problem Description
• Loss of heat/cool demand message from the comfort
control
• Loss of clock signal from indoor unit
Possible Causes/Solutions
• (Air Handler only) Comfort Control Mode on user
interface is set to 24volt mode when a communicating
comfort control is controlling system operation
- Comm LED and Bit Master LED will “OFF” and
16vDC will be measured at Data (D) line and
Common (B) on all communicating components
To Next Page
Loading...
