BoilerFaultCodesWhat the manual says
Manufacturer manualService message quantity of circulation water
What causes this fault?
This fault occurs when the boiler's sensors detect that water isn't flowing through the internal heat exchanger as quickly as it should. The most common reason is a buildup of sludge or debris in the system filter, or a circulating pump that is beginning to wear out and lose its pushing power.
This issue often surfaces in autumn when the heating is turned back on for the first time, as debris settled during the summer begins to circulate and block filters.
DIY fix possible
Check that at least two or three radiator valves are fully open to allow water flow.Ensure your system pressure is topped up to between 1.0 and 1.5 bar.Bleed your radiators to remove any trapped air that might be blocking circulation.
Avoid the next call-out bill
A cover plan would handle faults like S.85: no call-out fees, no surprise bills.
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