BoilerFaultCodesYour boiler is having trouble communicating with the sensor that monitors the temperature of your hot water cylinder.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Cylinder temperature sensor (NTC) not recognized
What causes this fault?
This fault occurs when the boiler's main control board loses the electrical connection to the sensor responsible for monitoring your hot water tank’s temperature. The most common reason is that the sensor itself has developed an internal fault or the wiring connecting it to the boiler has become loose or damaged over time.
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 Ad — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Worcester Bosch WR325 RSF 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.