Low
OUTSIDE SENSOR FAULT on Ideal Concord CXA 40-120

Your boiler is struggling because it has lost the signal from the weather sensor installed outside your home, meaning it cannot automatically adjust your heating based on the temperature outdoors.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

Outside sensor failure. Check wiring or change outside sensor.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Find a Gas Safe engineer
Search the official register →

Related guides you might find useful

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 →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →