Well as I've previously stated the new pump is in situ and set to max
speed, the problem of the upstairs rads is still there.. All rads are
open to supply now and I've found that they are all only warm to the
touch, one is totally cold, (it has been bled and both valves are
fully open, and it as previously been warm )..

The boiler is set to max - 80C so the manual says, but when I measure
the pipes at one of the furthest rads, I find 57C inflow 37
outflow..the rest are not so hot..

Is the Grundfos 50/15 the right pump for the job, do I need a pump
with a ' faster ' delivery?

... Boy I'll be glad when warmer weather comes and I can turn off the
CH


... Tony