Medium
A8 on Worcester Bosch Greenstar i Junior

Your boiler has lost its digital connection to the wireless thermostat or timer controller, meaning it no longer knows when to turn your heating on or off.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

Break in communication to weather compensating clip-in control or Greenstar Comfort II RF

From this model's manual
Verified against the Worcester Bosch Greenstar I Junior installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Locate the thermostat or programmer clipped into the front of the boiler or mounted on the wall.Check if the batteries in your wireless thermostat need replacing.Try resetting the connection between the transmitter and the receiver by following the pairing instructions in your user manual.

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