BoilerFaultCodesThe 6 most common faults
Your boiler has detected that the water pressure is too low for it to operate safely, which is why it has stopped working.
Locate the external filling loop, which is usually a flexible silver hose with two small valves.Slowly open both valves to allow water into the system while watching the display.Close both valves tightly once the display shows the pressure is between 1.0 and 1.5 bar.
Your boiler has stopped working because the water pressure inside the system has dropped too low for it to operate safely.
Locate the external filling loop, which is usually a silver flexible hose with two small valves.Slowly open both valves to allow water into the system while watching the pressure gauge.Close both valves tightly once the gauge reaches between 1.0 and 1.5 bar.
Your heater is trying to turn on but cannot light the burner, meaning your heating will not work until the system is reset or repaired.
Check that your gas meter has credit and the isolation valve is openEnsure other gas appliances in the home are workingPress and hold the 'RESET' button on the control panel for 3 seconds
Your boiler has tried to start but cannot light the flame, causing it to shut down for safety.
Check if your gas meter is turned on and other gas appliances are workingCheck if your credit meter has sufficient balancePress the reset button on the control panel once to see if the boiler restarts
Your boiler has switched itself off because it has become too hot and needs time to cool down safely.
Turn the boiler power off and wait at least 30 minutes for the unit to cool down.Check that all radiator valves are fully open and there are no blockages in the air grilles.Press the manual reset button on the control panel once the system is cool.
Your boiler has become too hot and has automatically shut down to prevent damage to the internal components.
Ensure all radiator valves are fully open and not turned off.Check that your system water pressure is at the correct level (usually 1.0 to 1.5 bar).Bleed your radiators to remove any trapped air that might be blocking water flow.
on the Johnson Starley Warmcair DW
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 Johnson Starley 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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