BoilerFaultCodesThe 6 most common faults
Your boiler has stopped working because the water pressure inside the system has risen too high for it to operate safely.
Locate a radiator in your home with a bleed valve.Place a cloth or small container under the valve.Open the bleed valve slowly to release water until the pressure gauge on the front of the boiler drops to between 1.0 and 1.5 bar.Close the bleed valve tightly once the pressure has returned to the normal range.
Your boiler has detected that the water pressure inside the system is currently too low to operate safely.
Locate the filling loop (a silver flexi-hose) beneath the boiler.Open the valves on the filling loop to allow cold mains water into the system.Watch the pressure gauge on the boiler until the needle reaches between 1.0 and 1.5 bar, then securely close the valves.
Your boiler is struggling to circulate water, either because there isn't enough water inside the system or because the internal pump has stopped working.
Check your boiler's pressure gauge and ensure it is between 1.0 and 1.5 bar.If the pressure is low, use the filling loop to top up the system to the correct range.Check that your heating circulating valves are open and not blocked.
Your boiler has too much water inside it, causing the pressure to rise to an unsafe level that has shut the system down.
Check that the filling loop valves are fully closed and not leaking water into the systemLocate a radiator bleed valve and use a key to drain a small amount of water into a containerMonitor the pressure gauge until it falls between 1.0 and 1.5 barPress the reset button to restart the boiler
Your boiler is struggling to detect water moving through the system and is currently trying to clear air from the pipes to fix itself.
Check that the boiler pressure is between 1.0 and 1.5 bar on the gauge.Ensure all radiator valves and isolation valves under the boiler are fully open.Gently bleed your radiators to remove any trapped air pockets.
Your boiler is failing to light the gas, meaning it cannot produce any heat or hot water.
Check if other gas appliances, like a hob, are working to ensure gas supply is activeEnsure your gas meter has credit if you use a pre-payment meterPress the Reset button on the boiler control panel once
on the Atag A200
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