BoilerFaultCodesThe 6 most common faults
Your boiler has tried to light several times but cannot start a flame, meaning your heating and hot water will not work.
Why it happens: This fault occurs when the boiler's control system attempts to light the burner but fails to detect a stable flame after several attempts. The most common reasons are a lack of gas reaching the unit, a worn-out ignition spark plug, or a fault within the internal gas valve that prevents the fuel from flowing correctly.
Check that your gas emergency control valve is in the 'on' positionIf you have a pre-payment meter, ensure you have sufficient creditPress the reset button for two seconds to see if the boiler restarts
Your boiler has shut down because it has detected that there is either not enough water in the system or it has become too hot.
Why it happens: This fault occurs when the boiler's internal temperature rises too quickly or the system lacks the water pressure needed to move heat away from the burner. The most common reasons are a seized circulation pump that isn't moving the water, or a significant blockage in the pipework causing the unit to overheat rapidly.
Check the pressure gauge on the boiler front or underneath; it should be between 1 and 1.5 bar.If the pressure is too low, use the filling loop to top up the water level.Ensure all radiator valves are open and that the pump is not making unusual grinding noises.Press the reset button once the pressure is restored.
Your boiler is failing to light or cannot detect the flame, meaning it has shut down to prevent unburned gas from building up.
Why it happens: This fault happens because the boiler has attempted to light three times but failed to establish or detect a steady flame. It is usually caused by a worn-out ignition spark or a problem with the gas supply reaching the burner. Without a confirmed flame, the boiler shuts down as a safety measure to prevent unburned gas from accumulating inside the unit.
Check that your gas emergency control valve and any internal gas lever valves are fully open.Verify if other gas appliances in your home, such as a hob, are working to confirm gas supply.If you have a prepayment meter, ensure you have sufficient credit.Press the reset button on the control panel once to see if the boiler restarts.
Your boiler has shut down because the water inside has become too hot, usually due to a lack of circulation or a blockage.
Why it happens: This fault occurs when the water leaving the boiler exceeds its safe temperature limit, causing the system to shut down for safety. The most common cause is a failed internal pump that isn't moving water away from the burner quickly enough, or a significant blockage within the heat exchanger that is restricting flow. It can also be triggered by a faulty sensor that is incorrectly reporting the water temperature as being too high.
Check that all radiator valves are fully open to allow water flowEnsure the boiler pressure gauge is between 1.0 and 1.5 barPress the reset button once the boiler has had time to cool down
Your boiler has shut down because the water returning to the unit is too hot, meaning heat isn't being transferred properly to your radiators or taps.
Why it happens: This fault occurs when the water coming back into the boiler is nearly as hot as the water going out, suggesting the heat has nowhere to go. The most common reasons are a pump failure that isn't moving the water around your house, or a blockage such as closed radiator valves or a clogged heat exchanger. It can also be caused by a faulty sensor that is incorrectly reporting the water temperature to the control board.
Check that all radiator valves (TRVs) are fully openEnsure the pump is running if visibleCheck that the bypass valve is not closedReset the boiler once the system has cooled down
Your boiler is overheating because water isn't moving through the system quickly enough to carry the heat away.
Why it happens: This fault occurs when the water temperature inside your boiler rises too quickly, causing the system to shut down for safety. The most common reasons are a pump that has failed to circulate water, a blockage in the pipework, or low water pressure, all of which prevent heat from being moved away from the burner. In some cases, air trapped in the system can also block the flow and trigger this overheat warning.
Check that your system water pressure is at least 1.0 bar on the pressure gauge.Ensure all radiator valves and internal stopcocks are fully open to allow water flow.Bleed all radiators to remove trapped air that might be blocking the circulation.
on the Remeha Quinta Ace 25
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