BoilerFaultCodesYour boiler has stopped working because a sensor that monitors the temperature of the water returning from your radiators has developed a fault.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Central heating return NTC fault
What causes this fault?
This fault occurs when the sensor responsible for measuring the temperature of the water returning to the boiler begins sending incorrect data or stops communicating entirely. The most common reason is that the internal components of the sensor have degraded over time or the electrical connection has become loose or damaged. Because the boiler can no longer accurately monitor the system temperature, it shuts down as a safety precaution to prevent overheating.
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 10 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Glow-worm 30ci Plus 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.