BoilerFaultCodesThe 6 most common faults
Your boiler has stopped working because the water pressure inside the system has dropped too low, which is usually easy to fix by topping it up.
Locate the filling loop (usually a silver flexible hose with one or two blue lever valves) underneath the boiler.Open the valve(s) slowly until you hear water running and watch the pressure gauge needle rise.Close the valves tightly once the gauge reaches 1.5 bar and check if the boiler restarts.
Your boiler has become too hot and has shut itself down as a safety precaution to prevent damage.
Check the pressure gauge is between 1 and 1.5 bar and top up if it is too lowEnsure all radiator valves and the boiler isolation valves are fully openBleed your radiators to remove any trapped air pocketsReset the boiler using the control knob or reset button
Your boiler is unable to flow water or gas properly and has stopped working to prevent damage.
Check that your gas emergency control valve is in the 'on' positionIf you have a prepay meter, check that you have enough creditReset the boiler by turning the control knob to 'RE' and back to 'on'
Your boiler has stopped working because the flame has gone out unexpectedly, often due to a temporary interruption in your gas supply or a sensor issue.
Check if other gas appliances, like a hob, are working to confirm gas is reaching the property.If you have a prepay meter, ensure you have credit and the valve is open.Press the 'Restart' button on the boiler control panel once to see if the flame re-establishes.
Your boiler is not receiving enough electrical power from your home's supply to operate safely and has shut down to protect its internal parts.
Full guide for Low Mains VoltageYour boiler has detected that water isn't moving through the system properly or a temperature sensor has failed, preventing it from heating your home safely.
Full guide for No Water Flow Thermistoron the Ideal Logic Code Combi
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 Ideal 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