BoilerFaultCodesYour boiler has shut down because its internal temperature sensors are giving inconsistent readings and can no longer monitor the heat safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Sensor drift lockout
What causes this fault?
This fault occurs when the boiler's control board detects that the two sensors monitoring water temperature are no longer agreeing with each other. It usually happens because one sensor has become inaccurate due to age or internal wear, causing the boiler to shut down for safety because it can no longer accurately track heat levels. In some cases, a loose or damaged connection in the wiring between these sensors and the main control board can also trigger the error.
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 E15 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
Affiliate links — we may earn a commission at no extra cost to you.