BoilerFaultCodesYour boiler has lost communication with the sensor that monitors the temperature outside your home, preventing it from adjusting its heat output efficiently.
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: Outdoor sensor fault
What causes this fault?
This fault occurs when the boiler is no longer receiving a consistent signal from the sensor located on the outside of your property. The most common reasons are physical damage to the external sensor unit or the electrical wiring being corroded or disconnected, which prevents the boiler from knowing how cold it is outside.
This fault is more frequent during autumn and winter as high winds, heavy rain, or freezing temperatures can displace the sensor or cause moisture to enter the wiring connections.
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 for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like E10 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Baxi Duo-tec/Megaflo is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
Affiliate links — we may earn a commission at no extra cost to you.