Hot water but no central heating after radiator install.

[Johntheo5]

You still have a problem there, more than likely air, it shouldn't be jumping about like that, if you set it to CC2, constant curve2, at 3M then you should get a steady 23/25W power wiyh a flowrate of 0.6/0.7m3/hr, if its set to CC3 at 6M, might be too high, even though it should'nt if no air, it might clear itself. CP3 at 4.5M might be worth trying but I certainly wouldn't advise any greater head than this.

 

[billyboy123]

Thanks, I just had it on the default setting but after you mentioned it I've read up on it and changed it to CC2.

 

[Johntheo5]

There are some quite good proportional pressure (PP) settings on that pump (far better than their Grundfos cousins) and worth a try especially if you have TRVs or (rad) zoning.
If you are flowing ~ 0.7m3/hr, ( 11.7LPM) on CC2 @3M now, then changing to PP3 should give ~ 0.76m3/hr,(12.7LPM) @ 3.55M but if the TRVs or zoning only require say half that flow then you will get close to it with a PP head of ~ 2.7M & possibly reduced noise level when the TRVs (if installed) throttle down. If only for interest, worth a try?.

 

[ChrisJP]

I took off the pump there was a bit of black crud, it spun when I tried to move it and I cleaned out the flutes. It's silent and I can't feel any vibrations when it's on settings 1 and 2 but it makes a hum when it's on setting 3. It's really really hot too.

That sounds as though the pump may not be working at all.