Low Warning
F027 on Intergas Xtreme / Xclusive

Your boiler has lost its connection to the outside temperature sensor, which usually helps the system adjust its heat based on the weather.

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

Short circuit of outdoor sensor

What causes this fault?

This fault occurs when the electrical signal from the outdoor sensor is interrupted, usually due to moisture getting into the sensor housing or damage to the external wiring. It can also be caused by a loose connection or a pinched wire somewhere between the boiler's control board and the outside wall.

This issue is more frequent during periods of heavy rain or high humidity, as moisture can penetrate the sensor's casing and cause the electrical circuit to short.

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 fault codes

F028View →

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 →