BoilerFaultCodesYour heat pump has stopped working because its internal safety sensor has detected that the water pressure is too high, causing the system to shut down for protection.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: High Pressure Sensor Error
What causes this fault?
This fault occurs when the system's internal pressure exceeds safe operating limits, often due to the expansion vessel failing or being incorrectly charged. It can also be triggered by a faulty sensor sending incorrect readings to the control board or by someone accidentally overfilling the system via the filling loop.
This issue often surfaces when the heating is first turned on after summer, as the expansion vessel is put under maximum stress when the water transitions from cold to hot.
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 High Pressure Sensor Error — 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.