Wilo Smart Pump vs Grundfos Alpha?

[Set Square]

My 10-year-old Grundfos 3-speed central heating pump is getting a bit noisy, and I intend to replace it in the near future. Since I also intend to fit TRVs to most radiators next summer, it would make sense to fit a pump whose delivery is automatically variable, and I have been considering getting a Grundfos Alpha.

In the latest Screwfix catalogue (#80) I see that they're selling Wilo Smart pumps - which appear to do more or less the same as an alpha - for 45 quid, which is not much more than half the price of an Alpha.

anyone have any experience of the Wilo (pronounced Vee-Lo according to their website) pump? Is it any good? *Does* it do the same as an Alpha? [From the picture it looks as if it may have less scope for adjustment]. Is it a case of "you gets what you pays for" - or do you pay through the nose for the Grundfos label?

[Slurp]

Hmmm - no direct knowledge of the Wilo, but I fitted a Grundfoss Alpha about

2 1/2 years ago.

The Grundfoss has an infinitely variable speed and a green LED which tells you its on - apart from that the specs seem similar.

Very pleased with it - the big advantage is the lack of noise as it auto adjusts the flow rate depending on demand - it is so quiet in fact that during the recent cold snap I can leave the pump on overnight and not be disturbed by any discernable rad/valve noise.

As a point of interest I paid £66 inc. vat for it at my local plumbers (full, not trade price) then.

Slurp

[Andy Hall]

Looking at the description, it seems as though Wilo have implemented some of the Alpha functionality.

I have an Alpha on my secondary (workshop) circuit and it performs very well. There is a continuously variable control, whereas it appears that the Wilo has three distinct settings.

Having said that, I am not sure that having that level of tweakability is important in a standalone pump. There is another Grundfos pump inside my boiler and that one is controlled on an analogue basis by the boiler controller - 20-100%. I can hook up a PC to the boiler and see what it's all doing - certainly the pump modulates according to demand, as does the burner.

In terms of the pricing, I think that if you shop around, and squeeze suppliers a bit, you should be able to get an Alpha for about £60 - the online places are doing them for £65.

[Set Square]

Thanks. I've now found some at £60-65 on line. When I first posted, I had only found some at 80-odd quid. So I guess you're saying "better the devil you know" - if it's not dramatically dearer than a cheaper model?

Ther only seems to be a couple of quid difference between the 15/50 and

15/60. A 15/50 would probably be adequate for my system. Is there any significant disadvantage in fitting a 15/60, and providing a bit of breathing space?

[Andy Hall]

Yes, I'm not saying that the Wilo is necessarily bad - no direct experience of it - but I do know that the Alpha works well.

What you could do is to look up the data for your existing pump in terms of the pressure/flow curves - especially for the setting that you have been using.

Then compare with the curves for the two Alpha models.

As long as you can achieve sensible adjustability, I think I'd go for the larger one. In my case I did, although I have quite long runs of

22mm between the location in the house where the heat exchanger is installed and the workshop so felt that a bit more availability of oomph wouldn't hurt.

[Mike Tomlinson]

In article , Set Square writes

Not the one you're looking at, but I replaced a dead pump (blowing fuses) with a Wilo Gold 50 a couple of years ago. It seems well made, came with a two year guarantee, and has worked with no problems. Despite the name, the Wilo is an interesting shade of green.