HVACopediaLennox · Furnace
E151 A2L sensor fault
What the control is telling you
Listed in the 107045-XX table as an A2L refrigerant sensor problem (communicating mode only); no action text given. The manual (including its troubleshooting section) gives no corrective procedure for this code; steps are general checks only.
Applies to: EL296UHV(X) series furnaces with integrated control 107045-XX only
Likely causes
- A2L sensor failed or disconnected
Test and repair steps
- Check the A2L sensor connector and wiring at the control.
- Refer to the A2L sensor literature for testing/replacement; this furnace manual provides no procedure.
Settings for these units
Recommended filter size by cabinet width · EL296UHV
| Cabinet width | Side return | Bottom return |
|---|---|---|
| 17-1/2 in. | 16 x 25 x 1 in. (1) | 16 x 25 x 1 in. (1) |
| 21 in. | 16 x 25 x 1 in. (1) | 20 x 25 x 1 in. (1) |
| 24-1/2 in. | 16 x 25 x 1 in. (2) | 24 x 25 x 1 in. (1) |
Number in brackets is the quantity of filters.
Filters are field supplied and installed outside the furnace; inspect monthly.
Recommended filter size by cabinet width · Lennox SL280UHV
| Cabinet width | Side return | Bottom return |
|---|---|---|
| 14-1/2 in. | 16 x 25 x 1 in. (1) | 14 x 25 x 1 in. (1) |
| 17-1/2 in. | 16 x 25 x 1 in. (1) | 16 x 25 x 1 in. (1) |
| 21 in. | 16 x 25 x 1 in. (1) | 20 x 25 x 1 in. (1) |
| 24-1/2 in. | 16 x 25 x 1 in. (2) | 24 x 25 x 1 in. (1) |
Number in brackets is filter quantity; filters are field supplied.
Never run the unit without a filter installed.
- Filter sizes by cabinet width · Lennox ML180UHE
Models that show this code
30 models in EL296UHV, Lennox SL280UHV, Lennox ML180UHE
Other codes on the same units
- E126 Control internal communication problem
- E131 Corrupted control parameters
- E150 A2L refrigerant leak alarm
- E152 Refrigerant leak sensor #2 fault
- E154 Refrigerant leak sensor #1 communication lost / wrong DIP setting
- E155 Refrigerant leak sensor #2 communication lost
- E160 Refrigerant leak sensor #1 wrong type
- E161 Refrigerant leak sensor #2 wrong type
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Source: Lennox EL296UHV(X) Unit Information / Service Literature, Ignition Control 107045-XX Diagnostic Codes table, p.41. Summarized in our own words; check the original manual for your model.
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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.