HVACopediaLennox · Furnace · Cooling
Cooling call on single-stage furnace blower
What happens, in order
- Control powers up and passes the self-check; polarity, ground and rollout are monitored the whole time
- Thermostat calls for cooling (Y/G)
- Compressor contactor and indoor blower are energized after a 2 second delay, blower on cooling speed
- The EAC terminal is energized with the blower
- Thermostat opens compressor stops, and the blower and EAC stay on for a 45 second off delay
- Low voltage, reversed polarity or poor ground are flagged on the LED but the control keeps answering the cooling call
Timings and thresholds
| Item | Value |
|---|---|
| Blower on delay | 2 s |
| Blower off delay | 45 s, not adjustable |
Codes you may see during this
Applies to: EL195UHNE, ML180UHEK
Models
More Lennox furnace sequences
- Single-stage furnace ignition retries and watchguard · Ignition
- Two-stage furnace ignition retries and watchguard · Ignition
- Single-stage furnace gas heating cycle · Heating
- Two-stage furnace heating with single-stage thermostat · Heating
- Two-stage variable speed furnace heating with two-stage thermostat · Heating
- Two-stage variable speed cooling call · Cooling
- Continuous fan with heat or cool calls · Standby/shutdown
Related
Lennox error codes · Lennox tips · Lennox parts · All Lennox sequences
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Source: Lennox EL195UHNE service manual Corp 1801-L1 (rev 04-2024), Sequence of Operation pp.9-10 and 49-54; Lennox ML180UHEK service manual 100166, Heating Ignition Sequence p.11 and Sequence of Operation pp.36-40. Written in our own words; timings can differ by model and software version, so check the manual for your exact unit.
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.