York 10 red flashes: The gas valve is energized with no call for heat

Source: York manual (PDF) (opens in a new tab) ↗ · Updated

Status code10 red flashesYork
What does York 10 red flashes mean?

The gas valve is energized with no call for heat. The main blower and the inducer blower run, and no ignition sequence starts, for as long as this condition exists.

Call a pro: jump to when to call a pro Equipment type: furnace
How it shows: LED behind the blower-door view port on a York TG9S. Each flash is 1/3 second on and 1/3 second off, then a 2-second pause: 10 red flashes

York TG9S 10 red flashes means the gas valve is energized when there is no call for heat. The main blower and the inducer run, and ignition does not start, until the condition clears. The manual says to check the gas valve and its wiring. One red flash is flame sensed with no call, which can be a valve that leaks or closes slowly. Ten red flashes is the valve being powered. If you smell gas, leave.

Likely causes

  • Gas valve fault
  • Gas valve wiring fault

Safe checks for 10 red flashes

  1. If you smell gas, leave and call the gas supplier from outside
  2. Techniciancheck the gas valve and the gas valve wiring
Safety firstIf you smell gas, do not touch any electrical switch or use a phone in the building; leave immediately and call your gas supplier from outside. Turn off electrical power at the furnace switch or breaker before opening any panel, and never bypass or jumper a limit, rollout or pressure switch. Gas valve, burner, venting, wiring and control-board work should be done by a licensed HVAC technician.

Capacitors can hold a charge after the power is off. Safety terms.

When to call a pro

Call a licensed HVAC technician. Do not keep resetting a furnace whose gas valve is powered when the thermostat is not calling.

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Related York codes

1 red flashFlame was sensed when there was11 red flashesThe main limit switch has opened2 red flashesThe pressure switch is closed when4 red flashesThe main limit switch has opened3 red flashesThe pressure switch contacts are open7 red flashesThe flame could not be established

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