High
AL73 on Vokera Mynute Vhe

Your boiler has detected a problem with the sensor that monitors the water temperature returning from your radiators, preventing the system from heating effectively.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

Return thermistor fault

From this model's manual
Verified against the Vokera Mynute Vhe installation & service manual, page 25.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

This fault occurs when the boiler's internal computer stops receiving a reliable signal from the sensor that monitors the temperature of the water returning to the unit. The most common reason is that the sensor itself has worn out and failed, or the electrical wiring connecting it to the main control board has developed a loose connection or a short circuit.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

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