HVAC Code Lookup

York Furnace: 5 Flashes

A York furnace LED pattern starting with 5 flashes matches 3 documented codes: 5 red flashes, 5 amber flashes (YP9C modulating), 5 red flashes (YP9C modulating). Watch the full pattern (short vs. long flashes) to tell them apart — all 3 are explained below.

Code 5 red flashes: The normally closed flame rollout switch has opened

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

The normally closed flame rollout switch has opened. Flame or hot combustion gas has spilled out of the burner box instead of going up the vent. The control goes into a hard lockout that only a power cycle will clear.

Manual wording: “5 RED FLASHES: This fault is indicated if the normally closed rollout switch opens. The rollout control is manually reset. Check for proper combustion air, proper inducer operation, and primary heat exchanger failure or burner problem. The control will enter a hard lockout...”

Documented for: TG8S, TG9S, TM9E, TM9X, TM8X, TM9T, TM8T

Likely causes, most common first

  1. Insufficient combustion air
  2. Inducer not drawing properly
  3. Cracked or failed primary heat exchanger
  4. Burner problem

What you can safely check yourself

  • Check the outside vent and combustion air pipe terminations for blockage
  • Make sure nothing is stored against the furnace blocking its air supply
  • If you smell exhaust fumes or have any CO alarm activity, leave the house and call for service from outside

When to call a technician

Call a licensed technician before running the furnace again. A rollout trip means combustion gas escaped the burner compartment, which can mean a cracked heat exchanger and a carbon monoxide risk. The rollout switch is a manual-reset safety device and must only be reset by a technician after the cause is found.

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

Sources

Full page for York code 5 red flashes

Code 5 amber flashes (YP9C modulating): The furnace has cut back its heating output because the combustion air or vent system is restricted

WarningShown as: Five amber flashes, two-second pause, repeating

The furnace has cut back its heating output because the combustion air or vent system is restricted. Above 4,000 feet altitude this can also be normal automatic derating.

Manual wording: “Five Amber Flashes - Heating capacity is reduced due to restriction in the combustion air or vent system. Check for blocked vent/air pipe or clogged condensate drain.”

Documented for: YP9C, YPLC modulating furnaces

Likely causes, most common first

  1. Blocked vent or air intake pipe
  2. Clogged condensate drain
  3. Normal altitude derating above 4,000 feet

What you can safely check yourself

  • Check the outside vent and intake pipe terminations for snow, ice, leaves or nests
  • Check the condensate drain and trap for a clog

When to call a technician

If the pipes and drain are clear and you are not at high altitude, have a technician check the venting and inducer.

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

Source

Full page for York code 5 amber flashes (YP9C modulating)

Code 5 red flashes (YP9C modulating): The rollout switch or the condensate pressure switch is open

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

Full page for York code 5 red flashes (YP9C modulating)

Other York codes