York Heartbeat Error Code
Normal operation — the ignition control board is powered and ready to respond to a heating demand.
Source: York 5/York_TECHNICAL-SUPPLEMENT-MILLENNIUM-SINGLE_Document_HVAC_EN.pdf
What does York Heartbeat mean?
A steady, repeating heartbeat blink on the gas-heat ignition control board (ICB) is the all-clear status. It confirms the board has power, has passed its self-check, and that every function needed to respond to a call for heat is available. No fault or error information is being displayed; the furnace is operating normally or waiting for the thermostat to call for heat.
Symptoms
- ICB LED pulses in a slow, even heartbeat pattern
- Furnace heats normally when the thermostat calls for heat
- No lockout, no flame or pressure faults are present
- Burners light and the blower cycles as expected
Common causes
- The control board is powered and has passed self-check
- All monitored safety inputs are in their expected state
- There is no active heating demand or the unit is heating normally
Ask the AskWhiz AI about York Heartbeat
AskWhiz
online
Diagnostic steps
Confirm the heartbeat pattern
Verify the LED is blinking in a steady, even rhythm rather than a counted burst of flashes, which would indicate a fault.
Check the call for heat
Set the thermostat above room temperature and confirm the furnace responds with a normal ignition sequence.
Observe a full heat cycle
Watch the inducer start, ignition occur, and the blower energize to confirm normal end-to-end operation.
Leave the unit in service
No corrective action is required for a heartbeat code; it indicates the control is healthy.
When to call a professional
A heartbeat code requires no service. If the furnace is not heating even though the board shows a steady heartbeat, the issue lies outside the ignition control — for example the thermostat, low-voltage wiring, or the unit control board. If you cannot get a normal heat cycle to start, contact a licensed HVAC technician to trace the call-for-heat signal back to its source.
Stop searching through PDFs. Our AI assistant on WhatsApp is trained on official York documentation and can diagnose this fault code and guide you through the repair in minutes.
5 free questions per bot in your browser — no signup.
Other York Error Codes
LED is steady off — no power to the control, or the control has suffered catastrophic damage.
LED is steady on — the control's microprocessor has not passed its self-check.
Induced draft pressure switch did not close — the switch failed to prove airflow within 10 seconds of the inducer starting.
Induced draft pressure switch stuck closed — the switch reads closed at the same moment a call for heat begins.
Flame could not be established — no flame was sensed in three consecutive ignition attempts (lockout).
Flame loss — an established flame dropped out five times during one heating cycle (lockout).
Open limit — 24 VAC was lost at the limit-switch input for six minutes or less during a call for heat.
Open rollout — 24 VAC was lost at the control's flame rollout switch input.
Gas valve failed to shut off — flame was sensed for more than 2 seconds after the gas valve output was turned off.
Indoor airflow failure / open limit — limit input lost 24 VAC for more than six minutes during a call for heat (hard lockout).
Gas valve miswire or gas valve relay fault — unexpected or missing 24 VAC at the gas valve outputs.