Squealing Grundfos ?

ScottMP

But recently we have had four different jobs with noisy circulators ?? We're being told that it might have to do with not getting all the air out but these have run for a week or so.

Anyone else having a problems ?

Scott

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aldo_2

pumps

If your (noisy) pumps are are piped at the highest point in your piping layout, and you do not have auto vents installed, then they will SCREAM!!

Mark Hunt

No issues here Scott


but on the last GB we installed a small washer got jammed in the impeller of the circ on the boiler manifold. No idea where it came from as it was not part of the circ. Took a couple days to work its way in there.

I will say this, even that did not cause the pump to burn out. She works like a charm!

Have you been able to figure out where the noise is coming from? Are these FC models?

Mark H

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ALF

Aldo is correct. Air left trapped in the system will accumulate in the rotor,this causes the water within the can to boil dry and the bearings to squeal. Be sure to burp the pump on start-up. Pumps mounted with the discharge facing downward can cause the air to become more or less permanently trapped in the rotor by the volute. Try to avoid this situation if possible. Just got back from a field trip to Grundfos in Fresno where we tore apart several pumps, got a lot smarter in a hurry.

ScottMP

O.K. guys

Two boiler system with air elimination, pumps in the basement, system preasure is 18lbs.

How can I get air trapped in the system ??

It worked fine for a week ??

Scott

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Big Ed

Burp

Jack up the systems water pressure all the way up to 28# to burp the air out of the rotor.. This was a tip a Grunfos support rep gave me.........

I am more of a Taco fan my sellf .

Paul Pollets

End Plugs

I've used Grundfos pumps for many years and have had very few issues or bad pumps. They're most reliable.

Some of the wet rotor pumps have an end plug at the end of the shaft which should be removed (with flat blade screwdriver) at first fill/startup until water spurts out. The plug has an O-ring and is refitted after the quick purge. Many techs forget this little detail.

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ScottMP

Hey Paul

This is the 15/58 FC. There is no end plug.

I also have been installing Grundfos for many years and like you have had no problmes. Now all of a sudden I do. We know how to burp the new circulators and honestly we should'nt have to do anything special. Once its up an running and circulating water the rotor should be wet !!

We put in over a hundred last year with No Problems.

Scott

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Hvacman

Squeeler

We had 2 fail this past Winter on the same zone... Temp heat situation, shortest zone closest to boiler, pump relay jumped out as controls were not finished, boiler temp up as reset control was not in....... Constant run plus elevated water temp cooked them.

Unknown

Had one squeeler last season,

changed it out and its been OK since,,I thought,,oh well. Then I had two(not on same job), 15-42 that fried the stator winding wire right at the plug-in point!

Dave

hot_rod

It could be the

internal check. If the pump is above the piping air will trap against that check and cause cavitation and on to dry bearings.

If you don't need the check remove it.

hot rod

Unknown

Good idea HR

I always consider the circs location and position, then decide whether to leave them or not.

Dave

Don \"Grumpy\" Walsh

Just this week I have pulled the checks out of four 15-42's. All of them have the water above the pumps, and they should always be wet. I have seven in this system and will probably need to pull the other three before long. I think there might be a problem here that is just starting to be noticed. All seven of these pumps have been in operation for more than three months, to have four of them act up in a two day period is very, very odd.

hot_rod

maybe they need a pinhole

just enough to burp some air through but not enough to "ghost" flow through them.

I've heard of this problem when the heating system sits over the summer and on initial start up the circs are air locked. With the check that close to the impeller, it only takes a small amount of air to mess with the impeller.

hot rod

Big Ed

The Grunfos

Had issues with their products over the years.

Bad first seasonal start ups,speed switches going bad,wire terminal blocks burning out, isolation flanges that leaked after you use them...

They handled the problems poorly in the past. Sorry to say It killed their market share in my area...

hot_rod

Big Ed

those were issues 10 years ago!

They have had those "wigglers" to free them up for at least 5 years and the highest starting torque, and the longest warranty in the industry.

Maybe you should give them another try.

hot rod

The Wire Nut

I had a couple of rubber ducks in the basment...

... except that they were red, had "grundfos 15-58FC" written on them, and were bloody loud to boot.

Grundfos came out to investigate, had the HVAC company flush the system (multiple air-bound loops were found), followed by a higher system pressure (to keep the air in solution on the 3rd floor) and we've been running silently ever since.

Weezbo

next time bust out the rubber mallet *~/:)

and *Boink the pump body a couple licks

worked for me:)

* small retraction,...according to my Newberrys better engineering practice guide the word Boink should be replaced with Bink

Larry Weingarten

One other thing...

... I haven't seen mentioned is position. Installing them in vertical lines where possible makes it hard for them to catch air. It's worked well for me ;~)

Yours, Larry

Uni R_3

I thought that too...

But then I hear not when discharging downwards.

Glenn Sossin_2

Bearings are ceramic 15 series

Grundofoss uses a ceramic bearing, which they claim will last longer, Taco uses a graphite bearing. When the pump is not installed correctly and/or system not purged adequately, air can get trapped by the bearing and it can result in squealing.

The pumps must have the housing mounted either horizontally or below the water line. I explain it to my customers as holding an open can of soda. Hold it upright, the soda stays in the can, hold it sideways, some soda stays in the can, hold it upside down, the soda runs out and the air fillis it in. They seem to be able to remember this analogy.

Possible solutions as discussed with the rep and NE sales manager - besides installing the pump housing in the correct postition, while purging, try to create water turbulance to catch/scoop the air in the pipes by opening/closing a valve quickly or squeezing/kinking intermittently the purge hose. For the UPS15-58FRC, they suggested trying to purge at all three speeds with a higher system pressure -20psi +. I like and find the quick open/close of a valve to be the easiest and best method.

Big Ed

I Don't Know

I do use them for their low volume range ..I don't use many but found a few that would not start up on low speed. One was on a pump station and the other was on a GB 142..

I do scare of easy .... Took me nearly 20 years to try Peerless again from their mid 80's fiasco..

Paul Rohrs_4

Ned Beatty

Scott, stop specifying and installing the "Ned Beatty" model Grundfos. That will stop the squealing.

Is it Friday yest or is it just me.....

Regards,

PR