HVACopediaYork furnace error codes
20 codes with causes and test steps, plus 2 settings tables.
| Code | Meaning | Severity |
|---|---|---|
| 1 red flash | Flame detected with gas valve off | Critical |
| 2 red flashes | Pressure switch closed when it should be open | Medium |
| 3 amber flashes | W2 call without W1 | Low |
| 3 double red flashes | Second-stage pressure switch not closing | Medium |
| 3 red flashes | Pressure switch open when it should be closed | High |
| 4 amber flashes | Cooling call (Y) without fan call (G) | Low |
| 4 red flashes | Main limit switch open | High |
| 5 red flashes | Rollout switch open / limit circuit open over 15 min | Critical |
| 6 red flashes | Pressure switch cycling lockout | Medium |
| 7 red flashes | Ignition failure lockout (retries) | High |
| 8 red flashes | Flame lost repeatedly (recycles) | High |
| 9 red flashes | Polarity reversed or bad ground | Medium |
| 10 red flashes | Gas valve powered with no heat call | Critical |
| 11 red flashes | Limit open 5-15 minutes - blower failure | High |
| 12 red flashes | Hot surface igniter open / igniter failure | High |
| 13 red flashes | High-fire pressure switch open | Medium |
| LED steady off | Board LED dark - no power to control | High |
| Rapid amber flash | Weak flame signal | Medium |
| Rapid red flash | Twinning error or wrong 24 V phasing | Medium |
| Steady on (any color) | LED lit solid - internal control fault | High |
Settings and specs
Clearance to combustibles
Clearances · York TM9V
| Side of furnace | Upflow | Downflow | Horizontal |
|---|---|---|---|
| Top / vent / rear / side / front | ? | ? | ? |
| Combustible floor | Yes | Yes (special sub-base only) | Yes |
| Closet | Yes | Yes | Yes |
| Line contact | No | No | Yes |
- Leave about 24 in. at the front and 18 in. at the side for service.
- Approved for alcove and attic installs.
- Inch clearances could not be rebuilt from the text export (cells run together; only 0 in. and 1 in. values appear) - read them off the unit label.
Source: York TM9V - -M9V 96% two-stage variable speed installation 1083294-UIM-A-0114.pdf - section Table 1 Unit Clearances to Combustibles
Filter size by return location
Filters · York TM9V
| Airflow | Cabinet | Side return filter | Bottom return filter |
|---|---|---|---|
| 1000 CFM | A | 16 x 25 in. | 14 x 25 in. |
| 1200 CFM | B | 16 x 25 in. | 16 x 25 in. |
| 1600 CFM | C | 16 x 25 in. | 20 x 25 in. |
| 2000 CFM | C | (2) 16 x 25 in. | 20 x 25 in. |
| 2000 CFM | D | (2) 16 x 25 in. | 22 x 25 in. |
- Sizes assume high velocity filters (600 FPM); throwaway filters must stay at or below 300 FPM.
- Filters go outside the cabinet - never inside the furnace.
- A single side return with one 16 x 25 filter is good to 1800 CFM; above that use two side returns, side + bottom, or a transition to a 20 x 25 filter.
Source: York TM9V - -M9V 96% two-stage variable speed installation 1083294-UIM-A-0114.pdf - section Table 4 Recommended Filter Sizes
Models covered
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.