"Martyn Pollard" wrote


Is there any reason why you aren't having a sealed system? It would make
life a lot easier for yourself and simplify the heating system. Also, low
water content boilers tend to operate better (quieter) on a sealed system
anyway.

Thanks Martyn

I am hoping that someone with serious experience of vented systems will
comment here!
If I can stabilise the system and prevent the pump over, modifying the
existing layout will be the most "comfortable" route.

Yes I have considered/am considering a sealed system, but I am concerned
about the age and state of the piping and its ability to cope with increased
pressure. The ground floor is solid concrete with buried pipes and some
plastic has been introduced upstairs (not sure if it's barrier quality).
The original install is 1970s and this is probably the worst period in UK
history for build and service quality IMHO.

Phil