I have recently moved into a larger house and am having soem problems with the radiators not getting hot, i have tried balancing which has helped but really my question is, is the pump i have strong enough. The house has 23 radiators of which 18 are large doubles, the pump is a grundfos 15/60, which i understand is a powerful domestic model, but i cant help thinking isnt up to the job.

Can anyone advise whether i can install a more powerful version, if so what, or how can i check that this is strong enough, i cant help feeling it isnt.

Thanks