BoilerFaultCodesTechnical description
No Water Flow
What causes this fault?
This fault occurs when the boiler's internal sensors detect that water isn't moving through the unit, which risks the heat exchanger overheating. The most common reasons are a seized internal pump, a build-up of sludge blocking the pipes, or a faulty pressure sensor that is incorrectly reporting a lack of water.
This issue is frequently seen at the start of autumn when heating systems are turned back on after sitting idle all summer, which can cause the pump to seize.
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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