BoilerFaultCodesThe 6 most common faults
Your boiler has stopped heating because the water pressure inside the system has dropped too low.
Locate the external or internal filling loop, which is a silver braided hose connected to your boiler pipes.Open the valves on the filling loop to allow cold water into the system until the pressure gauge reads between 1.0 and 1.5 bar.Close both valves tightly and ensure the boiler resets its display.
Your boiler has stopped working because it has detected that the water pressure inside the system is too low to run safely.
Locate the external filling loop, which is a silver braided hose connecting your central heating pipework to the mains water supply.Gradually open the valves on the filling loop to allow water into the system until the boiler's pressure gauge reads between 1.0 and 1.5 bar.Once the pressure is correct, ensure both valves on the filling loop are turned fully off and the system resets itself.
Your boiler has sensed that the water inside is heating up far too quickly for the system to handle safely, causing it to shut down to prevent damage.
Check your boiler pressure gauge to ensure it is within the green zone (usually 1-1.5 bar) and top up via the filling loop if low.Ensure all radiator valves are fully open to allow water to circulate freely.Bleed your radiators to remove any trapped air that might be blocking water flow.
Your boiler is struggling to detect the water pressure needed to run safely, likely because the system is low on water or a sensor is performing incorrectly.
Check your boiler pressure gauge; if it is below 1 bar, locate your external filling loopOpen the filling loop valves to top up the system pressure to between 1 and 1.5 barClose the valves tightly and restart the boiler to see if the code clears
Your boiler has lost the ability to measure the temperature of the water inside the system because a sensor or its wiring has become disconnected or faulty.
Full guide for F.00Your boiler has lost communication with a sensor that monitors the temperature of water returning to the system, causing the unit to stop working as a safety precaution.
Full guide for F.01on the Glow-worm Easicom3 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 Glow-worm 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
Avoid the next call-out bill
Monthly cover means no unexpected bills when your boiler breaks down.
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