BoilerFaultCodesThe 6 most common faults
Your boiler has stopped working because the water pressure inside the heating system has dropped too low.
Locate the filling loop (a flexible metal hose) connected to the underside of the boiler.Open the valves on the filling loop slowly to let water into the system.Watch the pressure gauge on the front of the boiler until the needle reaches 1.5 bar, then securely close the valves.
Your boiler has detected that water is not flowing around your heating system properly, so it has shut down to prevent damage.
Check your radiator valves are fully open to allow water flowEnsure the system pressure gauge is between 1 and 1.5 barIf the pressure is low, top it up using your boiler's filling loopCheck if your central heating pump is set to a higher speed if adjustable
Your boiler has detected that the water pressure inside the system is too high, which prevents it from operating safely.
Locate a radiator in your home that is easily accessible.Place a cloth or small container under the radiator bleed valve.Open the bleed valve slightly to release air and a small amount of water until the boiler's pressure gauge drops back into the green zone (typically 1.0 to 1.5 bar).Close the valve tightly once the pressure is normal.
Your boiler has stopped working because the water pressure inside the heating system has dropped too low.
Locate the filling loop, which is a silver braided hose with one or two valves connecting your mains water to your heating pipes.Open the valve(s) slowly to allow mains water into the system until the pressure gauge on the front of the boiler reads between 1.0 and 1.5 bar.Close the valve(s) tightly and check that the error code has cleared.
Your boiler has stopped working because it is unable to accurately measure the temperature of the water being sent to your radiators or taps.
Full guide for ALL 05Your boiler is trying to start but cannot detect a flame, so it has safely shut down to prevent gas from building up.
Full guide for ALL 06on the Sime Murelle Revolution 30
Based on parts cited in our fault code database. Your engineer will confirm what's actually needed after diagnosis.
Call a Gas Safe engineer if…
- You can smell gas or see signs of a leak
- The Sime shows an Emergency or High severity code
- The boiler keeps locking out after repeated resets
- You've tried the DIY checks and the fault hasn't cleared
- There's visible water leaking from the boiler
- The flame is yellow or orange instead of blue
Avoid the next call-out bill
Monthly cover means no unexpected bills when your boiler breaks down.
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