Noisy Grundfos pump and complex water needs

[Spokaloo]

Alright, the pressure from the wife has been exerted to a high enough degree that I need a longer term solution.

Currently have a 1.5HP Grundfos submersible in a well that's between 40 and 60 ft deep. All copper run to a pressure tank in a detached garage (40 gallons). Copper then runs through the ground and into our domestic at the foundation, and into an all copper distribution system in our house that was built in 1981. Right now, there's enough vibration when the well pump is running to cause a ton of noise. The builder did a mediocre job of retaining the pipe in the walls, so when we get vibration, it sounds like someone is operating a grinder in the house on a metal drum. No kidding, 30 db in some places.

I either need a solution to damp the vibration in the system between the pump and the house, or to replace the pump completely with a new setup.

Where it becomes complicated is we operate a well water fed 5.5 ton WaterFurnace geothermal heat pump with a desuperheater that feeds our hot water, and discharges the water out to the lake behind our home. Obviously we don't just have a standard domestic water need with showers and washing equipment, but we also flow water up to 24 hours a day on the coldest days of winter through the heat pump.

I had looked at a variable speed pump for this amount of water, but haven't seen remarkable reviews about the setups.

Any assistance with either knocking down the vibration or going with a new pump would be greatly appreciated.

E

 

[Cacher_Chick]

You might consider replacing a few feet of your incoming copper line with PEX to try isolating the vibration.

 

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[Valveman]

Must be something wrong with the pump. Submersible pumps should run very quite. A short piece of Pex or high pressure hose to isolate the well piping from the house will probably do the trick. When you vary the speed of a pump, it actually causes a lot more vibration, so don’t try that. If your pump is cycling on and off while the heat pump is running, the noise will come and go, come and go, come and go. If this is the case, cycling has probably already damaged your pump, which maybe the root of your whole problem.

 

[Masterpumpman]

Many years ago Franklin Electric advised me to install an additional running capacitor on a new pump that was vibrating when running. I did and it solved the problem. I'm not an electrician but I was advised that it had to do with the pump resinating. I recommend that you call Franklin Electric or Grundfos for a resolution. If it's noisy or vibrating it's a pump problem. As Valveman says a piece of high pressure hose may reduce the vibration but it's only a band-aid for the source of the problem. If your pump is cycling on and off while the heat pump is running I'd remommend you look at installing a Cycle Stop Valve as well.

 

[Alternety]

I agree that some isolation can to be added. I disagree that pex would do it. It is too stiff.

Insert a section of the softest piping you can find to provide vibration isolation. Make sure it is rated for any possible pressure. Something like butyl rubber comes to mind.

In addition, use a support clamp or two before this isolation segment that clamps the supply from the well with a rubber/absorptive material to help isolate vibration. If that does not help, I would investigate the pump itself. It may have a serious problem. Actually, it may have a serious problem even if what I have suggested works.

The pump itself should be very quiet. It is a balanced high speed spinning set of vanes. If it is not quiet, there could be damage causing an imbalance in the centrifugal rotor components which are rotating at high speed. This could be vane damage or a bearing problem. If it were me, I would try to get that sucker up out of the well and test it in a barrel of water to see if it is performing to expectations.

 

[LLigetfa]

I too agree that you need to isolate the vibrations in the piping and introduce a flex coupler. If there are any sharp 90 degree bends in the piping, consider re-piping with two 45's for every 90 or sweeps made of soft copper. A small bladder tank right at the point of entry could soften the pulses coming from the pipe.

In my house I deliberately strapped a loop of the poly pipe from the well to my floor joists so that I can "hear" when the pump is running.

 

[LLigetfa]

Yeas ago a friend living in trailer park was getting very loud jackhammer like noise in his plumbing. Turns out that a neighbor installed a pressure regulator that created water hammer. I had him install a small bladder tank which worked like a hammer stop.

 

[Spokaloo]

Thanks for the replies so far.

We bought the house in 2004, at that time it had a smaller heat pump (3.5 ton) and this well pump had been installed just a couple years prior. The pressure tank had a bladder failure in 2005, so we replaced that. In 2006 the heat pump grenaded, so we replaced it with a WaterFurnace 5.5 ton unit.

Moral of the story, I've been messing with the whole system today.

Heat pump should be using about 8gpm, max of 11gpm. I have a Challenger PC244 pressure tank that should hold 24 gallons in the bladder at the factory presets. Went through the whole unit, did a full system bleed-down, and captured 8 gallons from the pressure tank at full charge. 1/3 of the capacity it should have.

Tank is set to 38psi empty.

Pressure switch set to 40/68.

Cycling is spot on pressure wise, but pressurizing takes about 15-20 seconds, and it runs about 35-40 seconds to cut-in. Obviously this isn't good, and I'm sure the pump is destroyed from years of this system use.

Obviously I'm not thrilled with the prospect of $5k in water system repairs, esp for a pump that works but is just noisy. Also noting that some other part of the system isn't functioning as it should, but I can't diagnose it.

My only other idea is that the pressure tank is full of calcium. Just did the elements on the water heater last week, the bottom element was buried in calcium, there's literally 2 feet of sediment in the bottom. Maybe the same thing happened in the bladder?

E

 

[Spokaloo]

One additional piece, and I just figured this out myself:

The well head is 100' away from the house. The pressure tank is 50' from the house in a different building. I hadn't been accounting for the friction losses in the pipe run, so the minimum tank pressure of 38 wasn't really enough to feed the house adequately. I just upped the settings to 48-75, max tank air pressure gets up to 90psi, well below the 125psi working pressure max set by the manufacturer.

E