Lennox Unit controller

Lennox Unit controller Error Code 1

Unit controller

What It Means

  • ERRATIC POWER (single phase units)

Causes & actions from Lennox

How it shows
  • M4 alarm code: 1

• Power loss for 50ms or raw voltage is below 15VAC.. This may indicate that the unit power is dirty or is of low quality. • Check power connections. • The CORE Unit Controller will set an alarm “Erratic Power” whenever service is turned off due to detection of power loss. The CORE Unit Controller will shut itself down during an erratic power detection to protect its internally components and reset.

Applicable models & manual sources
Disclaimer: This information is for general reference. Code wording and instructions vary by model. Always follow the service manual for your exact unit.

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