At present I have a 25 y/old Potterton CF60 floor standing boiler with
an indirect Primatic cylinder . In about 10 days it is getting
replaced by an Alpha 32 condensing boiler .

The present boiler is very basic and to do anything to the CH
ssystem,for example replacing rads,it's ead easy to drain down the
system and then refill it after the work is done .

taking rad replacement or trv replacement as an example what will be
involved in doing that in my new system ...presumably the system will
have some sort of chemicals in it and it would be a waste to flush
them down the drain .

Stuart