CH pump replacement concerns.

[John.g]

I interpret from the pump curves that the flowrate is 1.02m3/hr, 17.0LPM which, depending on the rads output may give a dT of 15C to 20C.

 

[John.g]

 

[diydave]

Apologies John. Typo on my part. Indicated flow rate is indeed 1.3 cu m per hour and your delta T of between 15 to 20 deg C across the boiler is spot on. Delta T across radiators is very variable because of thermostatic valves. Delta T across boiler drops when hot water cylinder calls.