CodeRegistry
Brands
  1. Home
  2. Lennox
  3. PRODIGY 2.0 Unit Controller
  4. 36
About·Privacy·Terms

CodeRegistry — Your global library for technical solutions.

For your safety: always follow the equipment manufacturer’s official manuals. CodeRegistry is an independent help site and is not affiliated with the brands listed here.

36

Alarm 36 - Freeze-stat S53 Switch Open

Lennox · PRODIGY 2.0 Unit Controller

What does 36 mean?

The S53 freeze-stat switch has opened because the evaporator coil temperature dropped too low. The corresponding compressor is de-energized.

Common Causes

  • Evaporator coil temperature is too low
  • S53 freeze-stat switch malfunction

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Check the evaporator coil for ice buildup.

  2. 2

    Ensure proper airflow across the coil.

  3. 3

    Allow the coil to warm up; the switch should reset automatically.

  4. 4

    If the issue persists, check the S53 freeze-stat switch for proper operation.

Browse all codes in this manual (56)
Verified technical data. Last updated: April 2026

Related Faults

12Alarm 12 - High Pressure Switch S414Alarm 14 - High Pressure Switch S716Alarm 16 - High Pressure Switch S28
Source: Lennox PRODIGY 2.0 Unit Controller
Open Manual (Page 11)Search more codes in this manual