BoilerFaultCodesThe 6 most common faults
Your boiler has stopped working because the water pressure inside the heating system has dropped too low to operate safely.
Locate the filling loop, which is usually a flexible silver hose with one or two valves located underneath the boiler.Slowly open the valve(s) to allow cold mains water to enter the system until the pressure gauge on the front of the boiler reads between 1.0 and 1.5 bar.Close the valve(s) tightly to prevent over-pressurisation and check your boiler to see if the error code has cleared.
Your boiler has detected that the water pressure inside your heating system is too high and is shutting down to prevent damage.
Locate a radiator that has 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 back to the 'green' zone, usually around 1.5 bar.
Your boiler has stopped working because the water pressure inside the heating system has dropped too low.
Locate the filling loop, which is a silver braided hose connected to two valves beneath the boiler.Open both taps on the filling loop slowly to let water into the system until the pressure gauge reads between 1 and 1.5 bar.Close both taps tightly and check the boiler display to see if the fault code has cleared.
Your boiler has stopped working because the water pressure inside the heating system has dropped too low to operate safely.
Locate the external filling loop (a flexible silver hose pipe) underneath your boiler.Open the small valve or tap attached to the loop slowly until you hear water entering the system.Watch the pressure gauge on the front of the boiler until the needle reaches the green zone (typically 1.0 to 1.5 bar).Close the valve tightly and check that the error code has cleared.
Your boiler has stopped working because the water pressure inside the heating system has dropped too low.
Locate the external filling loop, which is usually a flexible metal or braided hose connected to two valves beneath the boiler.Open both valves slowly to allow water into the system until the pressure gauge on the front of the boiler reads between 1.0 and 1.5 bar.Close both valves tightly and ensure the pressure gauge stays steady.
Your boiler is trying to start but the flame is failing to light, stopping your heating and hot water from working.
Full guide for E01on the Heatline Sargon 30
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 Heatline 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