BoilerFaultCodesTechnical description
Over temperature on primary water circuit
What causes this fault?
This fault occurs when the water inside the boiler exceeds a safe temperature limit, causing the system to shut down to protect its internal components. The most common reasons are a failed pump that isn't moving water away from the heat exchanger quickly enough, or a blockage in the pipework restricting flow.
This issue is frequently seen during the first cold spell of autumn when pumps that have been idle all summer seize up upon being restarted.
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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