Medium
d.90 on Glow-worm Ultimate 3 25R

Your boiler is having trouble communicating with your wall-mounted thermostat, which might prevent your heating from turning on or off as requested.

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

Status of the eBUS room thermostat

From this model's manual
Verified against the Glow Worm Ultimate 3 25r installation & service manual, page 31.
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

Check that your thermostat has fresh batteries installed.Ensure the thermostat is securely connected to its wall plate.Restart your thermostat and check the wiring connections at the receiver if you are comfortable doing so.

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Related fault codes

d.91View →d.92View →

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