NOT OPERATING IN HEATING MODE High

Johnson Starley NOT OPERATING IN HEATING MODE Fault Code

Q: What does the Johnson Starley NOT OPERATING IN HEATING MODE fault code mean?

Your boiler is receiving power but fails to respond when the heating is scheduled to turn on, likely due to a communication failure between the controls and the unit.

Q: How much does it cost to fix Johnson Starley error code NOT OPERATING IN HEATING MODE?

Typical repair cost for the Johnson Starley NOT OPERATING IN HEATING MODE fault is £120-280 including labour.

Also written as NOTOPERATINGINHEATINGMODE — same fault.

The Johnson Starley NOT OPERATING IN HEATING MODE fault code means: your boiler is receiving power but fails to respond when the heating is scheduled to turn on, likely due to a communication failure between the controls and the unit.. It appears on 1 Johnson Starley model in our database.

Technical description: Heating timed terminal, programmer, MAF Stat, or Aquair PCB SL issues.

Typical repair cost £120-280 (including labour)

DIY fix possible

Check that the room thermostat is turned up higher than the current room temperature.Verify that the heating programmer or timer is set to the 'ON' or 'AUTO' position.Ensure the batteries in your wireless wall thermostat (if applicable) are fresh and working.

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Johnson Starley models that show the NOT OPERATING IN HEATING MODE fault code

Click a model for the full fault code list and model-specific repair notes.

Warmcair DW Repair: £120-280

Source

Johnson Starley NOT OPERATING IN HEATING MODE fault code information on this page is sourced and cross-checked against the official Johnson Starley service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026