Turn the furnace off and do not reset it. If you smell gas, leave the building without operating switches and contact the gas utility or emergency services from outside.
What does York code 1 Blink mean?
York furnace code 1 Blink means the control sensed flame without a call for heat on the supported control family. Confirm the model number and diagnostic chart inside the furnace door before replacing parts.
What causes York code 1 Blink?
- A gas valve leaking or stuck open
- A shorted flame-sensing circuit
- A failed integrated control board
Can I troubleshoot York code 1 Blink?
Turn the furnace off and do not reset it. If you smell gas, leave the building without operating switches and contact the gas utility or emergency services from outside.
How much does York code 1 Blink cost to fix?
A gas valve replacement typically costs between $300 and $1,000 nationally.
When should I call a technician?
Turn the furnace off and call a licensed technician immediately to test the gas valve and flame-proving circuit.
Symptoms this code causes
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.