problems with Grundfos 15-58 ??

ScottMP

we are in the midst of a learning curve for the factory and field.

I'll wait and see but its tough when a big customer in a custom home has to call and have us replace a squealing circulator thats only five months old.

Scott

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ScottMP

I have using Grundfos now

for about fifteen years and have Always been very happy.

But I gotta say that the last year I have had some problems. First we had about five squealers. We were told to burp them alittle on start up to allow the water to get to the cartridge. I'll except the answer but don't really think I should have to do anything like that.

Now I have had two that have been stuck and when we change speeds they start right up. Not working, change speed switch and off they go ???

I'm getting a little worried here.

Anyone else or am I " the only one " ?

Scott

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Mark Hunt_3

Squealers!

Scott, I have had several Grundfos pumps fail. One was on a Buderus Pri/sec manifold. Another was on a ST-150 indirect. I replaced then with Wilo Star 16S circs. Problem Solved!! I do believe the circulator war has started!

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mikea23

Kinda

I have found speed switch not locked in position and pump doesnt work. I also had 2 go bad that made so much noise that you had turn system off. No BS i could here it in the driveway. But looking back we probably put in over 200 last year. So that is not a very high failure rate for any product.

hot_rod

ICF's have changed the game

in my opinion. They tend to cause some air and possibly squeal if the circ starts without any lube (water)

It's not a brand spefic problem, really. You may in fact need to burp. I do, right at the discharge bolts.

Feature for feature Grundfos makes one of the best.

hot rod

Brad White_184

What about....

Curious observations:

The older Grundfos circs had a venting screw on the motor end and they have since done away with those. Any issues there?

The older ones had the "screwdriver arrow" switch which broke on more than one occasion, leaving me, I would hope, with the speed I wanted. Have not seen that as an issue in the current batch with the larger manual switch.

Does anyone have an issue removing the IFC? I feel more comfortable with a line-size flow check but cannot say I have had a problem. Burping has not been an issue thus far.

hot_rod

I'd rather the check come in the box.

It's much easier to install then "un-install" them." You don't always need, or want, the check feature.

The Alpha Pros came with the check in the box.

Pay attention to the position you mount IFC circs. If you put them on top of a primary loop, for example, just a tiny amount of air is needed to air lock them with the check so close to the volute.

Over the summer, any air will find those high points.

Brad, better to have them in the volute then in a iso valve or downstream for service-ability. I have seen them gunk up or get stuck open with debris. Hard to clean when they are in the piping or isovalves.

hot rod

Darrell

venting circs.

I tend a system that has multiple 15-58's above a pri/sec header like the post above. Originally they were all 15-42's without checks and then they had vent screws. Over time they have been replaced with the newer 15-58's with checks and no vents. The checks solved some not-to- bothersome ghost flow issues, but they do air lock...at least they did until I got tired of it and drilled and tapped an 1/8" hole and put in a coinvent just below the flange and check valve recess lookng out frontwards at about the four o'clock position. Seems like just putting in the coinvent fixed it...havn't had to go back since. The Taco's out there with the IFC's are just as bad at airlocking but I havn't tapped any of them yet. The fix takes about 5 minutes.

I have had two situation where the IFC on the Taco would not stop ghost flow...so I stopped at the local hardware store and picked up a stouter 5/16 spring and cut it to length...perfect and adustable too!

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ScottMP

Thats

how I have felt but the last year has bothered me. We put in hundreds, but a few out of a hundred is to much in my mind. I should'nt have any problems with a simple pump.

I can understand the burp on start up but what about coming back six months later and finding this problem ???

As for the speed switch its the same thing. A pump working fone for about a year and suddenly its stuck with no one touching the system ??

Scott

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hot_rod

Makes me wonder if a pin hole

in the check would keep the air lock issue away without allowing problematic ghost or gravity flow?

I still see the built in checks as more of a plus then minus. It sometimes takes some field experience before glitches are known

I doubt an engineer in the lab could mimic all the actual jobsite conditions.

hot rod

Mike D_7

Air bound check valves

I don't know a lot about hydronic systems, but most large diesel engine thermostats have either a very small vent hole or a small (>1/16") hole with a caged ball that floats & blocks the hole after the coolant bleeds through.

These holes are to prevent dry water pump starts and air locks at the thermostats. Maybe something similar is worth considering.