BoilerFaultCodesWhat the manual says
Manufacturer manualFlow sensor temperature exceeded
What causes this fault?
This fault occurs when the water leaving the boiler reaches an unsafe temperature because it isn't moving through the system fast enough. The most common reasons are a failing pump that can't push the water round, or a build-up of debris and sludge that has partially blocked the internal pipework.
This issue often comes to light in autumn when the heating is first turned on after summer, as the internal pump can seize up during long periods 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.
Avoid the next call-out bill
A cover plan would handle faults like E18: no call-out fees, no surprise bills.
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