BoilerFaultCodesYour boiler has shut down because it has detected an issue with a safety sensor or the pump that removes excess water from 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: Contact thermostat triggered. The surface-mounted thermostat or the condensate pump has triggered.
What causes this fault?
This fault occurs when a safety device detects that water isn't draining away correctly or the system is getting too hot. The most common reason is a blockage in the waste water pipe or a failure in the external pump that pushes excess fluid out of the boiler. To prevent internal damage or a leak, the boiler automatically shuts down as a protective measure.
This fault is significantly more common during freezing winter temperatures, as the external condensate pipe can freeze, causing water to back up into the boiler.
DIY fix possible
Check if the condensate pump is plugged in and switched onInspect the discharge pipe outside for blockages or freezing during cold weatherGently clear any visible debris from the pump filter if accessible
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If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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