BoilerFaultCodesTechnical description
HP flow sensor short / HP return sensor short
What causes this fault?
This fault occurs when the boiler's control board receives an impossible electrical signal from the sensors that monitor the water temperature. The most common reason is that the internal wiring or the sensors themselves have developed a short circuit, often due to natural wear or moisture ingress. Because the boiler can no longer safely monitor how hot the water is getting, it shuts down immediately to prevent overheating.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register →