York YP9C modulating gas furnace error codes

York YP9C modulating furnace flash codes

York's YP9C is a modulating gas furnace that signals faults with red flashes on its control board, counted in a pattern, and this directory lists the codes the brand documents. The count tells you what the furnace has detected, such as an open rollout switch, an open high limit, a gas valve communication error or a lockout after the flame was lost several times. Because a modulating furnace adjusts its flame in steps, its codes include faults with the valve and its signals.

Count the red flashes at the control board's window and write them down. Check the air filter and the registers first, since restricted airflow causes limit trips. Look for water around the furnace and a kinked condensate drain. Look outside at the intake and exhaust pipes for snow, leaves or a nest. Do not remove panels or bypass any switch. If you smell gas, leave the house and call the gas utility from outside.

The model and serial are on the rating plate inside the furnace door. York's service asks for both, and the model tells which family of codes applies. A yearly check by a qualified technician catches most problems before the cold weather.