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Red status lamp intermittent

Red status lamp blinking — Potential communication issue with heat pump

Nibe · SMO 20 Control Module

What does Red status lamp intermittent mean?

While not explicitly defined as blinking, a red status lamp indicates a malfunction. Intermittent red light could suggest a communication problem between the control module and the heat pump.

Common Causes

  • Loose or incorrect wiring between SMO 20 and heat pump
  • Faulty heat pump connection
  • Software incompatibility

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Check the electrical connections between the SMO 20 (terminals X2:19, X2:20, X2:21) and the heat pump are secure and correctly wired.

  2. 2

    Verify that the heat pump's software version is compatible with the SMO 20, referring to page 11 for details.

  3. 3

    Ensure the heat pump is correctly installed and powered.

  4. 4

    Attempt to reset the alarm on the SMO 20 display.

  5. 5

    Consult the heat pump's manual for specific troubleshooting related to its communication.

Browse all codes in this manual (5)
Verified technical data. Last updated: April 2026

Related Faults

Alarm bell iconAlarm bell icon on display — Malfunction detectedLow hot water temperature or lack of hot waterLow hot water temperature or no hot water — Potential causes identifiedNo display message but operational interferenceNo display message, but system not operating correctly — Basic checks needed
Source: Nibe SMO 20 Control Module
Open Manual (Page 19)Search more codes in this manual