My combî logîc 30 îs flashing f5 î have followed the înstructîons acc?

F codes are none resettable on these boilers, so trying to reset the boiler will not clear it. The thermistor is inside the case, that is part of the combustion cover, so under no circumstances should a none gas registered engineer EVER take off a case as they cannot then carry out the relevant 26:9 checks for safety. The fault is indeed a thermistor fault, but this MUST be replaced by a registered gas engineer, as if a homeowner takes off the case they can cause serious problems, and possibly void household insurance.

Someonewhoknowswhattheyareonabout
January 2017

The instructions suggest F5 signifies a fault with the return thermistor and says to Reset the appliance.

It goes on to say if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In Ireland, contact a Registered Gas Installer (RGII)

When you searched for yourself, information to help, you must have missed these:

https://www.youtube.com/watch?v=Pk8QJO67sIg

https://www.dhsspares.co.uk/product/ideal-175589-control-thermistor-flow-return-1780953

Actually, looking at the spare thermistor, it looks like a clip-on item so it may be worth having a visual check that all is well before going further.

You should be able to find and down load a manual for an Ideal Combi Logic 30 boiler easily enough

XXX
January 2017