BoilerFaultCodesWhat the manual says
Manufacturer manualBlocked Flue/Condensate
What causes this fault?
This fault occurs when the boiler's internal safety sensors detect that the waste gases or waste liquids cannot exit the unit safely. The most common reasons are a blockage in the plastic pipe that carries water away to a drain, or an obstruction in the large flue pipe on the outside of your property. If these pathways are restricted, the boiler will shut down to prevent hazardous fumes from backing up into the appliance.
This fault is frequently seen during periods of extreme cold when the external condensate pipe can freeze, causing liquid to back up into the boiler.
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 L0: no call-out fees, no surprise bills.
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