Medium
51 on Alpha Intec 50CS

Your boiler has lost its wireless connection to your room thermostat or controller, meaning it doesn't know 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

Climatic RF communication fault - Error between the communication of the Climatic transmitter and boiler receiver

From this model's manual
Verified against the Alpha Intec 50cs installation & service manual, page 48.
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 the batteries in your room thermostat and replace them with fresh ones.Turn the boiler off at the fused spur for 60 seconds to reset the receiver, then turn it back on.Attempt to re-pair the thermostat to the receiver following the instructions in your user manual.

Find a Gas Safe engineer
Search the official register →
Boiler cover options

Avoid the next call-out bill

A cover plan would handle faults like 51: no call-out fees, no surprise bills.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.

Related guides you might find useful

Boiler won't turn on — 9-step checklist

Work through these before the call-out.

Read →

Yellow or orange flame — CO safety

Safety-critical — turn off, read this.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →