BoilerFaultCodesThe 3 most common faults
01
Lockout lamp High DIY-safe
Your boiler has switched itself off because it has become too hot or there isn't enough water moving through the system.
What to try first
Check that your system water pressure is between 1 and 1.5 barEnsure all radiator valves and the boiler isolation valves are fully openWait for the unit to cool down and try pressing the reset button
02
Blocked condensate pipework High DIY-safe
Your boiler has switched itself off because the waste water pipe that carries away condensation is blocked or frozen, causing water to back up inside the unit.
What to try first
Locate the plastic pipe leading from the boiler to an outside drain.Check for any visible ice if the weather is freezing and gently thaw the pipe using a hot water bottle or warm (not boiling) water.Inspect the internal syphon trap under the boiler for any debris and carefully clear it if accessible.Reset the boiler once the blockage has been cleared.
03
Phase reversed neon High Engineer
Your boiler has detected that the electrical wiring coming from your home's power supply is connected back-to-front, which is preventing the system from starting up safely.
Full guide for Phase reversed neonon the Warmworld FFC 30/60
Flue thermostatOverheat limit thermostatCirculation pumpCondensate Syphon TrapExternal Condensate PipeworkTrace Heating Cable (optional preventative)
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 Warmworld 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