York TM9E furnace 4 amber flashes: Thermostat Wiring Warning
Professional repair
What do 4 amber LED flashes mean on a York TM9E furnace? The control received a thermostat Y signal without a G signal. York states heating and cooling still operate normally; the indication flags a wiring issue and is unrelated to the four-red limit fault.
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A qualified technician should check the thermostat and control wiring for the missing G signal. Homeowners should not rewire the thermostat or furnace control.
Possible causes
- Thermostat or control wiring not delivering a G signal 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 4 amber LED flashes mean on a York TM9E furnace?
The control received a thermostat Y signal without a G signal. York states heating and cooling still operate normally; the indication flags a wiring issue and is unrelated to the four-red limit fault.
How do I fix York TM9E furnace 4 amber flashes?
Because York says heating and cooling run normally, this can wait for a scheduled service visit. Mention any recent thermostat replacement or wiring work so the technician can trace and correct the missing G connection.
How much does it cost to fix York TM9E furnace 4 amber flashes?
The work is a wiring check and correction, so cost is mainly diagnostic and labor time. No part replacement is implied by this warning alone.
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.