BoilerFaultCodesThe 6 most common faults
Your boiler is unable to light the gas flame needed to heat your home or water.
Why it happens: This fault occurs when the boiler attempts to start up but cannot establish or detect a flame. The most common reasons include a lack of gas reaching the unit, a worn-out electrode that can no longer create a spark, or a build-up of carbon that prevents the sensor from 'seeing' the flame. It can also be caused by an internal electronic failure where the boiler's computer fails to open the gas valve correctly.
Check that your gas supply is turned on at the meterCheck if other gas appliances (like a hob) are workingPress the Reset button on the boiler control panelEnsure your condensate pipe has not frozen if it is very cold outside
Your boiler has shut down because it has detected it is getting too hot, likely due to a circulation problem or a faulty safety sensor.
Why it happens: This fault occurs when the water temperature inside your boiler exceeds a safe limit, triggering a safety switch to prevent damage. The most common reasons are a pump failure that stops water from moving or a buildup of debris that blocks the flow, causing the heat exchanger to overheat rapidly.
Check that your radiator valves are fully open to allow water to flow.Check that the boiler pressure is between 1 and 1.5 bar on the pressure gauge.Try resetting the boiler by turning the control knob to the 'OFF/RESET' position and then back to 'ON'.
Your boiler has detected that the water pressure is too low for it to operate safely, causing the system to shut down.
Why it happens: This fault occurs when the internal sensor detects that there isn't enough water inside the system to safely transfer heat. The most common reasons are a slow leak from a radiator valve or a loss of pressure in the expansion vessel, both of which cause the water level to drop over time.
Locate the external filling loop, which is usually a flexible silver hose under the boiler.Slowly open the valves to let water into the system while watching the pressure gauge.Close the valves once the needle reaches between 1.0 and 1.5 bar, then restart the boiler.
Your boiler has detected that the waste water trap is full or there is an issue with the sensor that monitors it, causing the system to shut down for safety.
Why it happens: This fault occurs when the boiler detects that the liquid waste produced during the heating process cannot drain away correctly, causing the internal trap to fill up. The most common reason is a blockage in the narrow drainage pipes or a build-up of debris within the condensate trap itself, which triggers a sensor to shut the system down to prevent water damage.
Check the white plastic pipe leading from the boiler for any signs of freezing if the weather is cold.Thaw any frozen external pipework using warm (not boiling) water or a heat pack.Reset the boiler by turning the mode selector switch to the 'OFF/RESET' position and then back to 'ON'.
Your boiler has failed to light because it cannot detect a flame or is struggling to vent correctly.
Why it happens: This fault occurs when the boiler attempts to start up but fails to sense a flame after several attempts. The most common reasons are a lack of gas reaching the burner, a faulty spark electrode that can't ignite the fuel, or a blockage in the chimney pipe preventing the air flow needed for combustion.
Check if other gas appliances in your home, like a cooker, are working.Ensure your gas meter has credit if you use a pre-payment meter.Check outside to ensure the flue pipe is not blocked by debris or ice.Reset the boiler by turning the selector switch to 'OFF/RESET' and then back to 'ON'.
Your boiler has failed to light or stay lit, which is often caused by a blocked condensate pipe or a sensor detecting a problem with the ignition process.
Why it happens: This fault occurs when the boiler tries to ignite but fails to establish a steady flame, or if the safety sensors detect that the waste water cannot drain away properly. The most common reason is a blockage in the condensate trap or external pipework, which causes water to back up into the heat exchanger and extinguish the burner. It can also be triggered by worn ignition components that can no longer create a strong enough spark to light the gas.
Locate the external plastic condensate pipe and check if it has frozen in cold weather.If frozen, carefully pour warm (not boiling) water over the pipe to melt the ice.Restart the boiler by turning the mode selector switch to 'Reset' and then back to the original position.
on the Vokera Mynute Vhe
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 Vokera 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