Boiler not getting hot enough

[doitmyself]

it is a natural process the flue gases are mildly acidic would not have happened if boiler serviced regularly

Thanks.

So are the flue gases eating into the hex, which will eventually become perforated?

 

[Gasmk1]

Thanks.

So are the flue gases eating into the hex, which will eventually become perforated?

not before the boiler is defunct, and not if you have it serviced regularly.