BoilerFaultCodesYour heat pump has stopped because the refrigerant gas is getting too hot, likely due to a blockage or restricted water flow through the system.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Condensing Temperature High Error
What causes this fault?
This fault occurs when the refrigerant gas inside the unit reaches a dangerously high temperature, causing the system to shut down for safety. The most common reason is that heat isn't being moved away from the unit fast enough, often due to a blockage in the pipes, a failing pump, or a build-up of sludge in the system filter.
DIY fix possible
Check that all your radiators are turned on and the valves are open.Ensure the external unit is clear of leaves, debris, or snow.Try resetting the unit at the control panel to see if the fault clears.
Find a Gas Safe engineer
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Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like 9.1.31 — 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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