BoilerFaultCodesYour boiler has stopped working because a sensor that measures the temperature of the water heading to your radiators is sending an incorrect or broken signal.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: The heating flow thermistor is too resistant.
What causes this fault?
This fault occurs when the main control board detects a signal from the heating sensor that is outside of its normal operating range. The most common reason is that the internal components of the sensor have degraded over time, causing it to report an impossible temperature, or there is a loose connection in the wiring leading back to the boiler's computer.
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 36 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Glow-worm Energysaver Combi 2 80 100 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.