HVAC Code Lookup

York Furnace 5 Red Flashes (YP9C Modulating)

Safety faultShown as: Five red flashes, two-second pause, repeating

The rollout switch or the condensate pressure switch is open. A rollout trip means flame or hot gas escaped the burner compartment; a condensate switch trip means the drain has backed up.

Manual wording: “Five Red Flashes - Rollout switch or condensate pressure switch open. Check the rollout switch(es) on the burner assembly. It is a manual reset switch... If it cannot be reset or if the switch trips again, contact a qualified serviceman.”

Documented for: YP9C, YPLC modulating furnaces

Likely causes, most common first

  1. Flame rollout switch tripped on the burner assembly
  2. Condensate pressure switch open from a backed-up drain

What you can safely check yourself

  • Check the condensate drain line and trap for a clog and clear standing water from the drain pan area
  • Check the outside vent and intake pipes for blockage
  • If you smell exhaust fumes or a CO alarm sounds, leave the house and call for service from outside

When to call a technician

The manual is explicit: if the rollout switch cannot be reset or trips again, contact a qualified serviceman. A repeat rollout can mean a cracked heat exchanger and a carbon monoxide risk - do not keep resetting it.

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

Source

Other York codes