Keep the furnace off. Do not reset a rollout switch. If you smell gas or a carbon-monoxide alarm sounds, leave the building and contact emergency services or the gas utility.
What does York code 5 Blinks mean?
York furnace code 5 Blinks means the flame-rollout switch is open on the supported control family. Confirm the model number and diagnostic chart inside the furnace door before replacing parts.
What causes York code 5 Blinks?
- A blocked flue or combustion-air path
- A burner or gas-pressure problem
- A damaged or restricted heat exchanger
Can I troubleshoot York code 5 Blinks?
Keep the furnace off. Do not reset a rollout switch. If you smell gas or a carbon-monoxide alarm sounds, leave the building and contact emergency services or the gas utility.
How much does York code 5 Blinks cost to fix?
A heat exchanger replacement typically costs between $500 and $3,500 nationally.
When should I call a technician?
Leave the furnace off and call a licensed technician for a combustion-safety inspection.
Sources and model scope
Fault codes vary by model and control board. Confirm the diagnostic chart inside your furnace panel or the official manual before acting.
Scope used here: Johnson Controls integrated furnace controls using the documented 1–12 red-flash table.
- Johnson Controls Unitary Products: Gas Furnace Installation Manual
272441-UIM-E-0513 · Johnson Controls integrated furnace controls with the 1–12 red-flash table in this manual; other model families may differ.
Compiled by Warmlo Editorial · Reviewed August 2026
This is general information, not professional advice. Gas, electrical, and combustion repairs can be dangerous — when in doubt, call a licensed technician.