HVACopedia

Lennox · Heat pump

65545 Cooling capacity alert

Medium severity

What the control is telling you

Prediction based on local climate data says cooling may not keep up on the hottest days; mild weather symptom can be longer run times. S30/S40 thermostat alert code 65545.

Applies to: Lennox communicating heat pumps incl. variable-capacity inverter units in S30/S40 smart thermostat systems

Likely causes

  • Dirty filter
  • Low refrigerant charge
  • TXV problem

Test and repair steps

  1. Check filter, charge and TXV operation.
  2. Clears on the next prediction.

Settings for these units

Save it for the next call

Star this code in the HVACopedia app and keep the whole library on your phone for jobs with no signal.

Open the app

Source: Lennox Residential Communicating Systems Alert Code Guide (V2) 100017 (3/2023), Table 2 Alert Codes and Troubleshooting, p.48. Summarized in our own words; check the original manual for your model.

Homeowner looking at this code? See what it means for you and when to call a technician.

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.