What pump would you recommend

[bopmac]

My central heating pump needs to be replaced.
The one fitted is a WILO SMART PUMP but I'm not sure this was up to the job. My system has 17 rads.
Can anyone suggest what brand, type, spec, pump I should replace it with

 

[namsag]

Grundfos 15/60 about 65 quid

 

[D_Hailsham]

Why do you think it is not up to the job?

 

[bopmac]

It has to feed 17 radiators over quite a long run of pipe work and the furthest ones away are not producing the heat they should. The system is balanced and working fine

 

[D_Hailsham]

It has to feed 17 radiators over quite a long run of pipe work and the furthest ones away are not producing the heat they should. The system is balanced and working fine

But, if the system was balanced properly, all the radiators would be producing the heat they should.

How do you know that the system is properly balanced?

Did you measure the temperature drop between the flow and return of each radiator and make sure they are the same?

Do you have thermostatic valves on your radiators? If so how did you allow for this when balancing?

The factors which determine the pump size are: (1) the frictional losses (head) in the Index Circuit - this usually is the circuit to the furthest radiator, but not always - it depends on the size of the radiators and pipes in the circuit; and (2) the mass flow rate of the water required to deliver the heat.

There is a more detailed explanation at:

http://www.cda.org.uk/Megab2/build/pub-150-copper-tubes-in-domestic-heating-systems.pdf

Which model Smart pump do you have?

 

[bengasman]

Grundfoss is my favorite

 

[ChrisR]

WHat's the boiler - model and power?

 

[micky p]

Can't go wrong with either Wilo or Grundfos. As for size it depends on how many storeys, pipe size / lenghts etc . maybe a 15/60 may do it.

 

[Softus]

http://www.grundfos.co.uk/

Click on "WebCAPS UK Specific Products", then on "Sizing".

 

[D_Hailsham]

http://www.grundfos.co.uk/

Click on "WebCAPS UK Specific Products", then on "Sizing".

I was going to suggest this, but thought better of it. It is a bit technical for the average DIYer.

 

[Softus]

I was going to suggest this, but thought better of it. It is a bit technical for the average DIYer.

He can always ask.