How much does it cost to fix Remeha error code 3 6.?

Typical repair cost for the Remeha 3 6. fault is £90-180 including labour.

3 6. High

Remeha 3 6. Fault Code

Q: What does the Remeha 3 6. fault code mean?

Your boiler has detected that a key internal thermometer is broken or disconnected, meaning it cannot safely monitor the temperature of the water leaving the unit.

Also written as 36 — same fault.

The Remeha 3 6. fault code means: your boiler has detected that a key internal thermometer is broken or disconnected, meaning it cannot safely monitor the temperature of the water leaving the unit.. It appears on 3 Remeha models in our database.

Technical description: Temp.sensor fault: Flow temperature sensor defective or not connected.

What causes the Remeha 3 6. fault?

This fault occurs when the boiler's control board loses communication with the sensor that measures the heat of the water being sent to your radiators. The most common reason is that the internal sensor has physically failed due to age or heat stress, though it can also be caused by loose wiring or dampness affecting the electrical connections.

Typical repair cost £90-180 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Remeha models that show the 3 6. fault code

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

Source

Remeha 3 6. fault code information on this page is sourced and cross-checked against the official Remeha service / installation manuals for each affected model.

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