York Gas Furnace: TM9Y
Re: Flashing Code 1
Code 1 = Flame sensed with no call for heat.
In a Code 1 situation, the furnace control board thinks that the gas valve is stuck on and the flame is still burning without a call for heat. Therefore, when a control board goes into a code 1, it will lock the inducer motor and blower motor on.
| Qty |
Possible Causes: |
|
Bad Control Board |
| 1 |
Sticking Gas Valve |
|
Shorted Flame Sensor |
| 1 |
Mis-Wired Low Pressure (LP) |
CHECKOUT:
1. Check Wiring
- Ensure that the flame sensor wiring is correct.
- On an LP gas furnace, a low gas pressure switch wires in series with the flame sensor.
2. Check Flame Sensor
- Visually check the flame sensor for rust flakes or other items that may cause a false reading.
- Check flame sensor Microamps when the burners shut-off.
- No Microamp signal but controller locks-out = Bad Control Board
3. Check Gas Valve
- Start the furnace with a call for heat
- After the burners have been lit for at least 30 seconds, remove the "W" wire.
- The burners should extinguish immediately.
- Delayed shut-off = Sticking Gas Valve