HVAC Code Lookup

York Furnace 10 Red Flashes

Safety faultShown as: Ten red flashes, then a two-second pause, repeating

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

Manual wording: “10 RED FLASHES: Gas valve energized with no call for heat. The main blower and inducer blower will run and no ignition sequence will be started as long as this condition exists. Check gas valve and gas valve wiring.”

Documented for: TG8S, TG9S, TM9E, TM9X, TM8X, TM9T, TM8T, TM9V, TM8Y, TM9Y

Likely causes, most common first

  1. Faulty gas valve
  2. Gas valve wiring fault

What you can safely check yourself

  • If you smell gas, leave the house and call the gas utility from outside

When to call a technician

The gas valve is being powered when it should not be. Call a licensed technician immediately - do not keep operating the furnace.

A York furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Sources

Other York codes