Grundfos 15-10F

van_9

I was just on the Grundfos website and these are really low flow, low head pumps. On the 10 loop radiant job you mentioned, how do they move any water? Website shows them as 25 W.

Uni R_3

Grundfos 15-10F - Iron bodied...

Do these actually exist? I've seen them referenced in some of the Grundfos literature but try and find one!

The much much more expensive bronze 15-10B is easy to find but ideally I'd like to find an 15-10F in a flanged model.

Dave_4

15-10F

Yes, they do exist!

I just installed 6 of them; 3 for injection and 3 for my radiant loops.

Nobody has them in stock and they ship direct from the factory. Expect about 2 weeks to receive them. I don't know why they aren't more popular given all the radiant installs.

I have one circulating a manifold with (10) 5/16 hePex loops (180-200' foot lengths). Works great!

Tim

Uni R_3

Excellent!

Thanks Tim, did they have flanges?

Also, do you recall if they are 25 or 33watts?

Dave_4

Flanges

Flanges would be either the up15-10F or up15-10FR

Tim P._2

Yes, the 10F has flanges (F= flanges, FR= rotated flanges).

Off the top of my head, I believe they are 40w. I will check and get back to you.

Uni R_3

No need Tim - Many Thanks

Thanks Tim. I was never sure whether F meant flange or Fe(iron) because the B is bronze.

Anyway, I got a SKU from Grundfos so I'm set...

Dave_4

I used the Wirsbo ADS to design the system. The flow and head loss for the quicktrak system is within the parameters of the pump.

I also am using the same pump for 1/2 hePex with radiant track (also 10 loops 250+- lengths) and my basement slab (also 1/2 hepex).

I put a lot of faith in the ADS program, as the local plumbers I know all go by rule-of-thumb, "what we usually do" and "we never used a pump that small".

When I bought my Biasi 3-section, I was told "we never sold a boiler this small". WADS says 32k required and the B-10 is at 67k.

I was skeptical, but everything is working great. Just don't leave the front door open on the coldest day of the winter or it'll be a while before the room gets back up to temp

WADS saved me a lot of headaches. Free to try and at $99 to buy is a steal. I highly recommend.

Just curious as to what people are calculating the head loss is in their radiant systems?

Tim

Uni R_3

Got price on 15-10F today... something is bizarre!

Why on earth would one of these cost almost double the price of a UP 15-58FC? I could see if it were bronze or stainless...

ALH_4

numbers

I bet Grundfos sells 500 UP15-58FC's for every UP15-10F they sell.

Maybe a 15-58 on low would work ok for 20W extra?

We all become slaves to misapplied zone pumps. I wonder if this is part of the reason Grundfos introduced the UP15-58FC which is significantly less expensive than the UPS15-42F. It might actually get people to try a lower curve.

Uni R_3

Very true Andrew

Yet I'm sure these 'lil guys would be far better choices for many of those circuits we see on the wall'o pumps shots here.

Oh well... I tried.

Dave_4

In my case, the 15-10F was $4 more than the 15-58FC, both being significantly less than $100.

Considering the long circulation times, the $4 was well worth the energy savings.

Tim

Tim P._2

The pumps are indeed labeled 25w.

Tim