BoilerFaultCodesThe 6 most common faults
Your boiler has detected that the water pressure is either too low or too high for it to run safely, or there is a problem with the sensor that measures this pressure.
Check the pressure gauge on your system, which should ideally be between 1.0 and 1.5 bar when the system is cold.If the pressure is below 1.0 bar, use the external filling loop valves to top up the water pressure.If the pressure is above 3.0 bar, you may need to bleed a radiator to release the excess pressure.Reset the boiler once the correct pressure is reached.
Your boiler has become too hot and has shut down as a safety precaution to prevent damage.
Check that all radiator valves are fully open and not turned off.Ensure the external heating pump is running and hasn't become stuck.Wait for the boiler to cool down and press the 'Reset' button.
Your boiler has detected that water is not circulating properly through the unit, causing it to shut down for safety.
Check that your system pressure is between 1.0 and 1.5 bar on the pressure gauge.Ensure all radiator valves are fully open and any zone valves are functioning.Try bleeding your radiators to remove any trapped air that could be blocking water flow.Reset the boiler once you have checked the water pressure and valves.
Your boiler has detected that the water pressure is too low to operate safely, meaning it needs more water added to the system.
Locate the external filling loop, which is usually a flexible silver hose with one or two small taps.Slowly open the tap(s) until you hear water flowing and the pressure gauge reaches between 1.0 and 1.5 bar.Close the tap(s) tightly and restart the boiler to clear the fault code.
Your boiler has shut down because it detected it was getting too hot or a temperature sensor has failed.
Check that your radiator valves are open to allow water to flow.Ensure your system pressure is topped up to between 1.0 and 1.5 bar.Wait 15 minutes for the unit to cool down, then press the 'Reset' button.
Your boiler has stopped working because it cannot detect the water movement it expects when the pump starts up.
Check that your home's main water stopcock and all boiler valves are fully openEnsure all radiator valves (TRVs) are turned to their highest settingCheck the boiler pressure gauge and top up to 1.5 bar if it is too lowRestart the boiler using the reset button to see if the fault clears
on the Atag iR Regular
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 Atag 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