BoilerFaultCodesThe 6 most common faults
Your boiler has detected that water is not circulating properly, most likely because the system pressure has dropped too low to operate safely.
Check the pressure gauge on the front of the boiler; if it is below 1 bar, your system pressure is too low.Locate the filling loop (a silver braided hose or a small key valve) underneath the boiler.Open the filling valve slowly until the needle on the gauge reaches between 1 and 1.5 bar, then close the valve tightly.
Your boiler has switched itself off because it has detected an issue with the water flow through your heating system, likely due to low water pressure or a stuck pump.
Check your boiler's pressure gauge and ensure it is between 1 and 1.5 barIf the pressure is low, locate the filling loop and open the valves to top up the system to 1.5 barOnce topped up, reset your boiler using the reset button
Your boiler has stopped working because there is either not enough water inside the system or an internal part that moves the water around has stopped running.
Check the pressure gauge on the front of the boiler; if it reads below 1 bar, your system needs to be re-pressurisedLocate your external filling loop (a flexible metal or braided hose connecting two pipes)Open the valves on the filling loop to allow cold mains water in until the needle reaches 1.5 bar, then ensure the valves are tightly closed
Your boiler has lost the water pressure it needs to circulate heat, likely due to a minor leak or the system needing a top-up.
Locate the filling loop, which is usually a small silver or braided hose under the boiler.Open the valves on the filling loop to allow cold water into the system.Watch the pressure gauge until it reaches the green zone (typically 1.0 to 1.5 bar) and then firmly close both valves.
Your boiler has stopped working because it cannot light the internal flame or keep it burning.
Full guide for 20Your boiler has detected that it is overheating and has automatically switched itself off to prevent damage.
Full guide for 21on the Baxi System 35/60 / 60/100
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 Baxi 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