BoilerFaultCodesThe 5 most common faults
Your boiler is struggling to ignite or detect a flame, causing the system to stop as a safety precaution.
Why it happens: This fault occurs when the boiler tries to light but fails to establish or sense a stable flame within the set time limit. The most common reasons include a lack of gas reaching the burner, worn-out ignition components that can no longer create a spark, or a dirty sensor that cannot tell the boiler the flame is safely lit.
Check that your gas meter is turned on and other gas appliances like the hob are working.If you have a prepaid gas meter, verify that you have sufficient credit.Press and hold the 'Reset' button for two seconds and wait up to three minutes for the venting cycle to complete.
Your boiler has detected that the water inside is getting too hot too quickly, usually because there isn't enough water pressure or the water isn't moving through the pipes properly.
Why it happens: This fault occurs when the heat inside the boiler cannot be carried away by the water quickly enough, causing the system to protect itself from damage. The most common reasons are a lack of water pressure, a blockage in the pipework, or a pump that has failed and stopped moving the water around. It can also happen if too much air is trapped in the boiler, creating an air pocket that stops the flow.
Check the pressure gauge on the front of the boiler; if it is below 1.0, top it up using the filling loop.Ensure all radiator valves are fully open to allow water to circulate.Bleed your radiators to remove any trapped air that might be blocking the flow.
Your boiler has detected that water is not circulating correctly, often because there is trapped air or the system pressure is too low.
Why it happens: This fault occurs when the boiler's internal sensors detect that the temperatures are the wrong way around or not changing as expected, suggesting water isn't moving through the unit. The most common reasons are a lack of water pressure, a buildup of trapped air pockets, or a pump that has seized and can no longer push water around your radiators. Essentially, the boiler is shutting down to prevent itself from overheating because the heat it produces has nowhere to go.
Check the pressure gauge and top up to 1.5 bar if it is lowBleed all radiators to remove trapped airEnsure all radiator valves and isolation valves are fully openReset the boiler using the reset button
Your boiler has detected a problem with its internal temperature sensors, meaning it cannot accurately monitor the water temperature and has shut down as a safety precaution.
Why it happens: This fault occurs when the boiler's internal computer loses communication with the sensors that monitor water temperature. It is usually caused by an electrical failure within the sensor itself or a loose connection in the wiring, preventing the boiler from knowing if it is safe to continue heating.
Full guide for é0Your boiler's internal computer has suffered a software failure and can no longer process the settings needed to operate safely.
Why it happens: This fault occurs when the boiler's internal memory becomes corrupted and loses the essential factory settings required to run. The most common reason is an electrical surge or a terminal component failure on the control board that prevents the computer from reading its own software.
Full guide for e45on the Remeha Avanta Plus 35c
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 Remeha 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