High
E33 on ECA Confeo Premix HM

Your boiler has detected a fault with the sensor that monitors water returning to the unit, causing it to shut down for safety.

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

Error on Temperature Sensor for Return Sensor (lockout) — return water temperature sensor in short or open circuit; press Reset; if persists notify ECA authorised service

From this model's manual
Verified against the Eca Confeo Premix Hm installation & service manual, page 41.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

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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