BoilerFaultCodesThe 6 most common faults
Your boiler has stopped working because a control switch inside may be in the wrong position or the unit has become too cold.
Check if your boiler or the room it is housed in has dropped below 5°C and allow it to warm up if necessary.Check if the gas valve mode switch inside the boiler casing is set to the correct normal operating position.Reset the boiler using the reset button once the environment has warmed up.
Your boiler has detected low water pressure or trapped air in the system, which stops it from operating safely.
Locate the filling loop underneath the boiler.Open the valves slowly to top the system pressure up to between 1.0 and 1.5 bar on the pressure gauge.Close the valves firmly and bleed any trapped air from your radiators.
Your boiler is not detecting the correct airflow needed to operate safely, so it has shut itself down to prevent any issues.
Full guide for E00-730Your boiler is unable to regulate the gas supply correctly, which is preventing it from firing up to provide your heating and hot water.
Full guide for E80-450Your boiler is failing to ignite the flame needed to produce heat and hot water.
Full guide for E00-720Your boiler has temporarily stopped working because it cannot safely detect the burner flame.
Full guide for E01 612on the Worcester Bosch 24/28/35 CDi MkII
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 Worcester Bosch 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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