BoilerFaultCodesTechnical description
Check pump connections. Check water flow. Change pump.
What causes this fault?
This fault occurs when the boiler's internal sensors detect that water isn't moving through the unit quickly enough to safely carry heat away. The most common reasons are a mechanical failure of the pump motor, an electrical connection issue, or a blockage caused by a buildup of debris in the system's pipework.
This issue frequently appears in autumn when heating systems are switched back on after being idle all summer, often because the pump has seized during the months of inactivity.
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.
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