Medium
51 on Alpha Intec 12S

Your boiler has lost its wireless connection with your thermostat or remote control, meaning they can no longer talk to each other to manage your heating.

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

From this model's manual
Verified against the Alpha/Alpha Intec S 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

Check the batteries in your wireless thermostat and replace them if they are low.Ensure the wireless receiver near the boiler is powered on and hasn't been blocked by metal objects.Try resetting the boiler and the thermostat to re-establish the wireless link.

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.

All 24 fault codes on the Intec 12S

Seeing a different code? Every code this model can display, in one place.

0102030405060810121516202425272931373843444647

Related guides you might find useful

Thermostat not working

Change the batteries first, even if the screen still works.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →