How much does it cost to fix Grant error code Red neon?

Typical repair cost for the Grant Red neon fault is £80-200 including labour.

Red neon High

Grant Red neon Fault Code

Q: What does the Grant Red neon fault code mean?

Your boiler has switched itself off because it has reached an internal temperature that is too high, preventing potential damage or safety issues.

Also written as REDNEON — same fault.

The Grant Red neon fault code means: your boiler has switched itself off because it has reached an internal temperature that is too high, preventing potential damage or safety issues.. It appears on 4 Grant models in our database.

Technical description: Safety overheat thermostat has operated and automatically switched off the boiler in the case of a control malfunction causing overheating.

Typical repair cost £80-200 (including labour)

DIY fix possible

Wait for the boiler to cool down completely (at least 20-30 minutes).Locate the overheat reset button under the screw-on cap on the control panel.Press the button firmly until you hear a click, then restart the boiler.

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Grant models that show the Red neon fault code

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

Source

Grant Red neon fault code information on this page is sourced and cross-checked against the official Grant service / installation manuals for each affected model.

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