BoilerFaultCodesThe 6 most common faults
Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
Locate the external filling loop, which is usually a small silver braided hose with one or two valves located underneath your boiler.Gradually open the valve(s) to allow mains water into the system while watching the pressure gauge on the front panel.Stop filling once the needle reaches the green zone, typically between 1.0 and 1.5 bar, then ensure the valve(s) are fully closed.
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 with one or two valves underneath your boiler.Open the valve(s) slowly to let water into the system until the pressure gauge needle on the front of the boiler reaches between 1 and 1.5 bar.Close the valve(s) tightly and the boiler should automatically restart.
Your boiler has stopped working because the water pressure inside the heating system has dropped too low.
Locate the filling loop (usually a silver braided hose under the boiler).Open the valves on the filling loop to allow cold mains water into the system.Monitor the pressure gauge on the front of the boiler until the needle reaches the green zone (typically 1.0 to 1.5 bar).Close both valves tightly and ensure the boiler resets.
Your boiler is failing to light because it cannot detect a flame, meaning you currently have no heating or hot water.
Full guide for F1Your boiler has detected that it is getting too hot and has automatically shut itself down to prevent damage.
Full guide for F2Your boiler's temperature sensor is providing incorrect information, so the system has shut down to prevent overheating.
Full guide for F3on the Heatline Capriz 25 System
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