BoilerFaultCodesWhat the manual says
Manufacturer manualCirculation Bleed radiators, check system water pressure; if low refill via filling loop Bleed radiators, check system water pressure; if low refill via filling loop
What causes this fault?
This fault occurs when water cannot travel through the boiler’s internal heat exchanger quickly enough to carry heat away. The most common reasons are trapped air pockets creating a blockage, a buildup of sludge in the system, or the internal pump failing to spin correctly.
This issue is frequently seen in autumn when heating systems are switched back on after being idle all summer, which can cause internal pump components 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.
Avoid the next call-out bill
A cover plan would handle faults like E2: no call-out fees, no surprise bills.
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