Main Multipoint FF water heater red light blinking

[momomo345]

My water heater frequently goes in protection mode a few seconds after starting a hot water upstairs which is quite annoying because I need to press on a button for 5 seconds to reset it and make it work again.

I have a specialist having a look several time but the water heater is all clean and looks new (it's from 2014). He says it might be a heat sensor issue.

I have seen elsewhere it can be a problem with the restrictor in the flue. Is it worth trying to open it and remove the restrictor? Can I try myself or do I need a specialist for that? We have a very short flue in a reversed L shape

Any other ideas on what can cause the issue?

Manual is here:
https://ams3.digitaloceanspaces.com/boiler-manuals/main/Main-multipoint-ff-water-heater-ISIM.pdf

 

[ianmcd]

NO you cant touch anything to do with any part of the flue yourself

 

[momomo345]

manufacturer advise to change it.

 

[ianmcd]

they never advised that you do it

 

[momomo345]

I mean they advised to have a specialist changing the whole unit.

 

[ianmcd]

I have seen elsewhere it can be a problem with the restrictor in the flue. Is it worth trying to open it and remove the restrictor? Can I try myself or do I need a specialist for that

I mean they advised to have a specialist changing the whole unit.

Make your mind up