York Gas Furnace: TM9Y
Re: Flashing Code 6
Code 6 = Pressure switch opened (Code 3) 4 times during a run cycle.
► This is a "Soft Lockout" which will automatically reset after 1 hour.
► There are 3 pressure switches on this furnace. PS1 (1st Stage Switch usually .90") and PS3 (Condensate Switch usually .20") are wired in series to the pressure switch input.
►The PS2 (2nd Stage Switch) wires in separately and will cause a Code 13.
Qty |
Possible Causes: |
|
Bad Inducer Motor |
|
Water in Vent |
7 |
Water in Inducer/Clogged Drain |
|
Improper Condensate Drainage |
|
Bad .90 Pressure Switch |
3 |
Bad .20 Pressure Switch |
|
Water in Pressure Switch / Tubing |
CHECKOUT:
1. Check Inducer Motor Operation
- Start the furnace with a call for heat from the thermostat.
- Observe and listen to the inducer motor operation.
- Listen for sounds of water in vent piping.
- If water is gurgling in vent, look for low spots that will hold water.
- Pipe must have constant slope back toward furnace.
2. Check Pressure Switches
- PS1 (1st Stage Switch)
- Check for 24VAC between "C" on the terminal block and the Blk/Org wire on PS1.
- Check for 24VAC between "C" on the terminal block and the Wht wire on PS1.
- Power On Both Sides = Switch Closed ⇒ Check PS3 Switch
- Power on One Side Only = Switch Open ⇒ Check PS1 Pressure
- PS3 (Condensate Switch)
- Check for 24VAC between "C" on the terminal block and the Wht wire on PS3.
- Check for 24VAC between "C" on the terminal block and the Red/Grn wire on PS3.
- Power On Both Sides = Switch Closed
- Power on One Side Only = Switch Open ⇒ Check PS3 Pressure
- Check PS1 Pressure
- Use a pressure meter to check the pressure at the PS1 switch.
- Watch for water in the pressure switch hoses.
- Compare actual pressure to pressure rating on the switch.
- Pressure near or below rating = Blocked or Restricted Vent
- Pressure well above rating + Open Switch = Bad Switch or Water in Switch
- Water in Switch is usually caused by a mis-run pressure switch hose.
- Check PS3 Pressure
- Use a pressure meter to check the pressure at the PS3 switch.
- Compare actual pressure to pressure rating on the switch.
- Pressure near or below rating = Blocked Drain
- Pressure well above rating + Open Switch = Bad Switch
3. Check Condensate Drainage
- Check the Robber Drain Coupling on the inducer outlet.
- On horizontal runs, make sure the drain outlets are pointed slightly down-hill.
- Remove drain hoses.
- Water running out of coupling = Clogged Drainage
- ► Make sure there is nothing inside the drain coupling clogging the drain outlet.
- Check the drain hoses from the collector box.
- Make sure all drain hoses are clear and have a downward slope.
- ► Make sure the drain outlets are not clogged.
- ! Make sure there is an "Air-Gap" in the PVC drain immediately upon exiting the furnace !
- Any trap after the collector box before an air gap will cause drainage issues.
- In extreme cold conditions, be cautious of Frozen Drains.