BoilerFaultCodesThe 6 most common faults
Your boiler has stopped because the water pressure inside the system has dropped too low or risen too high, preventing it from heating safely.
Check the pressure gauge on the front of the boiler; if it is below 1 bar, locate the metal filling loop underneath.Open the filling loop valves slowly to allow mains water into the system until the gauge reads between 1 and 1.5 bar.Close both valves tightly and restart the boiler.
Your boiler has switched itself off because the water level inside the heating system has dropped too low.
Locate the external filling loop, usually a silver flexible hose with one or two valves attached to your boiler pipes.Open the valve(s) slowly to allow 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 restart the boiler.
Your boiler's control panel is registering a button as being permanently pressed or stuck, which is preventing it from operating correctly.
Ensure no debris, dust, or moisture is trapped under the buttons of the control panel.Gently press and release each button on the interface several times to see if it frees a stuck mechanism.Turn the boiler off at the fused spur for 60 seconds to perform a hard reset, then turn it back on.
Your boiler is struggling to pump water around your radiators, so it has turned itself off to prevent overheating.
Check that all radiator valves throughout the house are fully openEnsure the central heating system pressure is at the correct level, usually between 1 and 1.5 barBleed all radiators to ensure there is no trapped air preventing water flow
Your boiler has lost its connection to its wall controller or thermostat, meaning it cannot receive signals to turn on your heating or hot water.
Check the batteries in your remote thermostat unit and replace them if necessaryTurn the boiler off at the fused spur or mains power for 60 seconds, then turn it back on to reset the connectionCheck that the signal receiver box near the boiler is powered on and flashing correctly
Your boiler is failing to light the internal flame, which means it cannot provide heat or hot water.
Full guide for 01on the Alpha Eco
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 Alpha 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