BoilerFaultCodesYour heat pump has detected a pressure level that is too high within the system and has shut down to prevent damage.
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 Switch Operated
What causes this fault?
This fault occurs when the internal pressure of the refrigerant or the water system exceeds safe operating limits, triggering a safety switch to protect the unit. The most common reasons are a lack of water flow through the heat pump caused by a blocked filter or a failing circulation pump, which prevents heat from being transferred away quickly enough.
This fault is more common during the first cold snaps of autumn or winter when the system is under higher load after being idle during the summer months.
DIY fix possible
Check that all radiator valves are fully openEnsure there are no external debris or plants blocking the airflow to the outdoor unitCheck that the internal central heating valves (usually near the cylinder) are in the open position
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A boiler cover plan would cover faults like LBE — no call-out fees, no surprises.
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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.
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