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 filling loop, which is usually a small silver braided hose or a pair of taps underneath the boiler.Open the valves slowly to allow mains water into the system while watching the pressure gauge on the front of the boiler.Stop filling once the needle reaches the green zone, typically between 1.0 and 1.5 bar, then tightly close both valves.
Your boiler has stopped working because the water pressure inside the heating system has dropped too low.
Locate the filling loop, which is usually a metal braided hose underneath the boiler.Open the two valves on the filling loop to allow cold mains water into the system.Watch the pressure gauge on the front of the boiler until it reaches 1.5 bar, then firmly close both valves.
Your boiler's internal water pressure is currently too high, which can put unnecessary strain on the system's internal safety components.
Locate a radiator in your home that is easily accessibleUse a radiator bleed key to gently open the bleed valveRelease a small amount of water into a cloth or container until the pressure gauge on the boiler drops to between 1.0 and 1.5 bar
Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
Locate the filling loop (a flexible metal hose) connected to the pipework underneath your boiler.Open the valves at both ends of the filling loop slowly to let water enter the system.Watch the pressure gauge on the front of the boiler until the needle reaches the green zone (typically between 1.0 and 1.5 bar).Once the pressure is correct, firmly close both valves and ensure the loop is disconnected if it is a removable type.
Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
Locate the filling loop (a silver flexi-hose) connected to the underside of the boiler.Open the small tap or valve on the filling loop to allow cold mains water into the heating 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 the valve tightly and ensure the boiler resets itself.
Your boiler is failing to light the internal flame needed to produce heat or hot water.
Full guide for F1on the Saunier Duval Themaclassic Plus F30E
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 Saunier Duval 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