York TM9E furnace 6 red flashes: Pressure Switch Lockout
Professional repair
What do 6 red LED flashes mean on a York TM9E furnace? The pressure switch opened four times during one heat call. The control then locks out for one hour before an automatic retry.
This condition involves the gas or combustion side. If you smell gas or a CO alarm sounds: leave, then call your gas utility. Diagnostic info here is reference — combustion repairs are for licensed technicians. All six emergency signs →
Safe checks before calling
From the ground, check the outdoor intake and exhaust terminations for snow, ice or debris. Report what you see to the technician; do not take the venting apart.
A technician needs to find why pressure proving keeps dropping out, checking the inducer, vent and pressure switch. The switch must not be adjusted or bypassed.
Possible causes
- Blocked vent, which may show at the outdoor termination DIY-CHECKABLE
- Inducer or pressure switch problem found during diagnosis TECH
Parts for this code
No model-verified part number is listed here. Have the fault diagnosed and the correct part matched to your furnace before ordering.
Questions about this code
What do 6 red LED flashes mean on a York TM9E furnace?
The pressure switch opened four times during one heat call. The control then locks out for one hour before an automatic retry.
How do I fix York TM9E furnace 6 red flashes?
The automatic retry after an hour does not mean the cause is gone. Schedule service even if heat returns, and note how often the furnace started and stopped before the lockout. Avoid restarting it to test.
How much does it cost to fix York TM9E furnace 6 red flashes?
Intermittent pressure loss can take more diagnostic time to pin down. Parts and labor then depend on whether the inducer, vent or switch is responsible.
Applies to
TM9E
Different York generations use different code maps. If your series isn't listed, don't assume this meaning — check your blower-door label.
Verified against YORK TM9E Series Installation Manual — Single Stage ECM Residential Gas Furnaces, p.34
Last verified 2026-10-07 · page updated 2026-10-07 · how we verify
Related York furnace codes
These codes use the same york tm9e single-stage ecm tri-color led control system.