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York Error Codes & Diagnostic Codes

Updated · by Aurora Star Tech Inc.

York error codes and diagnostic codes: look up a code to see what it means, the likely causes and the steps to fix it.

York error codes by equipment type

York Furnace error codes

CodeMeaning
1 red flashFlame detected with gas valve off
2 red flashesPressure switch closed when it should be open
3 amber flashesW2 call without W1
3 double red flashesSecond-stage pressure switch not closing
3 red flashesPressure switch open when it should be closed
4 amber flashesCooling call (Y) without fan call (G)
4 red flashesMain limit switch open
5 red flashesRollout switch open / limit circuit open over 15 min
6 red flashesPressure switch cycling lockout
7 red flashesIgnition failure lockout (retries)
8 red flashesFlame lost repeatedly (recycles)
9 red flashesPolarity reversed or bad ground
10 red flashesGas valve powered with no heat call
11 red flashesLimit open 5-15 minutes - blower failure
12 red flashesHot surface igniter open / igniter failure
13 red flashesHigh-fire pressure switch open
LED steady offBoard LED dark - no power to control
Rapid amber flashWeak flame signal
Rapid red flashTwinning error or wrong 24 V phasing
Steady on (any color)LED lit solid - internal control fault

Find codes by York model

TM9V040A10TM9V060B12TM9V080B12TM9V080C16TM9V100C16TM9V100C20TM9V120D20

General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.

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