"robf" wrote in message
m...

Aside from my other post re. repairing existing boiler. I am tempted
by the higher efficiencies of the condensing boilers but are there
hidden problems in upgrading an existing installation.
I do not need a combined boiler - I have HW cylinder and pump /
valves.
Concerns I have are -:
Cleanliness of existing system - any prerequisites?

Have it flushed out. Put in flushing agent before scrapping it. Flush with
fresh water about three times.

Will existing rads be ok - presuming
that water temp is lower????

Some modern modulating condensing boilers are designed for existing 80C temp
installations. It modulates to suit. If it needs full 80C it gives it.
Most of the time it will be on part load

If you buy a boiler which modulates the internal pump, then just remove the
existing remote pump. Simple.


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