BoilerFaultCodesThe 6 most common faults
Your boiler has automatically stopped working because the water pressure inside your heating system has dropped too low.
Locate the two small valves (filling loop) connected to the pipework underneath your boiler.Slowly open the valves to allow mains water into the system while watching the pressure gauge on the front of the boiler.Once the needle reaches the green zone (typically between 1.0 and 1.5 bar), tightly close both valves.
Your boiler has detected that the water pressure inside your heating system is too high and has safely shut itself down to prevent damage.
Locate a radiator in your home, preferably one upstairs.Using a radiator bleed key, open the bleed valve slightly to let a small amount of water out into a container.Monitor the pressure gauge on the front of your boiler until it drops back into the green zone (typically between 1.0 and 1.5 bar), then tightly close the radiator bleed valve.
Your boiler has stopped working because the water pressure inside the heating system has become too high.
Locate a radiator with a bleed valve and a small key.Place a cloth or small container under the valve to catch water.Slowly open the valve to let a little water out until the pressure gauge on the front of the boiler drops to between 1.0 and 1.5 bar.
Your boiler has detected that the water pressure inside your heating system is either too low or too high, so it has safely shut down to prevent damage.
Locate the external filling loop, which is usually a small silver braided hose with one or two valves underneath the boiler.Gradually open the valve(s) to let water in until the pressure gauge on the front of the boiler reads between 1.0 and 1.5 bar.Close the valve(s) tightly to stop the flow of water and check if the error code clears.
Your boiler has automatically shut down because the water pressure inside the system has become too high.
Locate a radiator in your home that is easily accessible.Place a cloth or small container under the radiator bleed valve.Slowly open the valve to release water until the pressure gauge on the boiler shows between 1.0 and 1.5 bar, then securely close the valve.
Your boiler has detected that the water pressure inside the system is too low for it to operate safely and efficiently.
Locate the external filling loop, which is a flexible silver hose connected to the underside of the boiler.Open the small valve or tap attached to the loop to allow mains water to enter the system.Watch the pressure gauge on the front of the boiler until the needle reaches the green zone (usually 1.0 to 1.5 bar).Close the valve firmly and ensure the flexible hose is disconnected if required.
on the Atag Q 25CR
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