York Furnace Error Codes & Fix Guides
All FixCode Guide coverage for York furnace error codes: start with the complete code list, or jump to a deep-dive guide for a specific code. Everything is verified against York manufacturer documentation.
Guides in this section
York Furnace Error Codes List: Every Code ExplainedYork Furnace 3 Flashes: What the Blinking Light Means & FixesYork Furnace 4 Flashes: What the Blinking Light Means & FixesYork Furnace 2 Flashes: What the Blinking Light Means & FixesYork Furnace 7 Flashes: Ignition Lockout — Meaning & FixesHow to Reset York Furnace Error Codes
Most searched York furnace codes
| Code | Meaning |
|---|---|
| 2 red flashes | Pressure switch stuck closed — the pressure switch contacts are closed when they should be open. BOTH tri-colour generations agree on this code. Standard boards confirm it at the start of each heat cycle, before the inducer runs; modulating boards phrase the same report precisely: pressure switch closed with inducer pressure below the pressure switch setpoint (the switch is closed when it should be open). |
| 3 red flashes | Pressure switch stuck open — the pressure switch contacts are open when they should be closed: the normally open contact did not close after the inducer was energised, so draft was never proven and the furnace will not light. The modulating generation phrases the same report more precisely: pressure switch open with inducer pressure above the pressure switch setpoint (the switch is open when it should be closed). |
| 4 red flashes | Limit switch open — a limit switch has opened its normally closed contacts because the furnace overheated, and the control runs the supply air blower and inducer while the condition exists. GENERATION NOTE: on modulating boards York's definition is wider — high limit switch open OR defective temperature sensor OR 24-volt fuse open. On standard boards the detailed manual text defines 4 red flashes as the main limit switch only (GF9S wording: a primary or auxiliary limit switch). |
| 7 red flashes | Ignition lockout — lockout due to no ignition: flame could not be established in three ignition tries. BOTH tri-colour generations agree on this code. The control locks out for one hour, then tries again. The standard manuals detail it as a no-light condition that occurred 3 times (2 retries) during the call for heat before locking out. |