New central heating pump needed - what type?

shinjukumaster

We have a combi boiler (ICI Caldaie Solar 2000) which is installed on a system with 11 radiators. 3 of the radiators were added (in an extension) after the combi was originally fitted. Also, two of the recentlly fitted radiators are microbore (10mm) - the rest of the system is 15mm. It seems the circulation pump has gone, and I'm wondering if we need to replace the pump like-for-like, or use an upgraded model.

As best I recall, the fitted pump is a WILO 15/50 type. I understand that the 15/60 type is better suited to larger systems (not sure if this is classed as a large system?), and also microbore systems.

Looking at the energy specs, most of the 15/50 pumps seem to be 'B' rated, and the 15/60 types 'C' rated. Is that simply because a more powerful motor is fitted?

And is there any benefit to replace with one brand over another? e.g. Grundfos, WILO, unbranded? And is any one brand quieter than the other? The WILO is a little bit noisy on speed No2, or 3, so quiet is good.

Thanks!

ormus

a normal house or flat will be ok with a 15/50 pump. a large tall house will use the 15/60.
(more head).
the grundfoss is better IMHO.
get the grundfoss alpha pump if you like to brag in the local pub.

gas4you

I have never come across, or heard of your combi boiler, but assuming it is fairly standard, in that the pump is built in, then it will have to be a like for like pump change, unless you are fortunate enough for the manufacturers to have fitted a standard pump to it.

shinjukumaster

Its an old un. British made. I think it is a std. WILO pump. Thanks

gas4you

You may be lucky and be able to fit a 15/60 head.