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Ideal Boiler Fault Codes

Fault code Fault


Low water pressure - you can manually reset your boiler pressure


Flame loss


Fan fault 

F4 / L4

Flow thermistor 

F5 / L5

Return thermistor


Outside sensor failure 


Low mains voltage 

F9 / L9

Unconfigured PCB


Flow temp too high or no water flow - you can manually set the flow temperature to the lowest setting if this doesn't work we recommend getting an engineer


Ignition lockout - you can manually fix this with our frozen condensate guide here


False flame lockout - reset your boiler and this should fix the issue


5 boiler resets in 15 minutes - turn the electricity to your boiler off then on to fix the issue


Negative differential flow/return rate 


Flow/return differential > 50°C 


Diverter valve in mid-position for service - turn all of the knobs clockwise, turn the boiler off and on, then click restart

Baxi affordable repair combi heat only combi boiler

Safety Warning

When your Ideal boiler error codes or fault lights flash, don’t do any repair work that involves working with gas as you are required to be Gas Safe Registered by law.

Here at Boiler Plan all our engineers are Gas Safe Registered and will do an amazing job with any Ideal boiler repair work you may need.

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