CodeRegistry
Brands
  1. Home
  2. Lennox
  3. PRODIGY 2.0 Unit Controller
  4. ON ALARM
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.

ON ALARM

ON ALARM — Unit is off due to active alarms

Lennox · PRODIGY 2.0 Unit Controller

What does ON ALARM mean?

The unit has shut down because one or more active alarms have been detected that require the system to halt operation. The specific alarm codes are displayed on the main system status screen.

Common Causes

  • One or more critical system alarms are active.
  • A safety condition has been triggered.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Check the system status screen for active alarm codes.

  2. 2

    Address the specific conditions indicated by the alarm codes.

  3. 3

    Clear the active alarms as per their respective troubleshooting steps.

  4. 4

    If unable to identify or resolve the alarm, contact a service professional.

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 96)Search more codes in this manual