Grundfos 16S07-8 the right replacement pump?

[justler]

I have a 200ft well with the pump sitting at about 180ft.

The pump currently in the well is a 1HP Zoeller from Lowes (1452-0006 - https://www.zoellerathome.com/content/literature/025095-Zoeller-4inSub-Instr-2-wire.pdf). Supposed to be 10GPM at 175ft.

I have an 86 Gallon A.O. Smith pressure tank with a 23 gallon draw down on a 40/60 pressure switch.

I'm having issues where it is not refilling the pressure tank as quickly as it used to and when the pump kicks on and i'm in the shower, the pressure is very low and is the only device on in the house. I've also jumped out and made sure the pressure drop wasn't just in the shower by turning on another faucet and it wasn't. Shower is 2.5gpm max if the valve I have activates the shower head and shower wand.

I had a similar problem prevously with a 4 year old Aermotor pump (1/2HP) last year but the pressure there was less than with this Zoeller pump. It was a trickle in comparison. This Zoeller pump was put in to replace it.

I have been looking at Grundfos pumps thinking part of the issue was that i'm not sure Aermotor or Zoeller at home are quality pumps. I also think possibly the Aermotor pump was undersized at 1/2hp and sitting at almost 200ft and the Zoeller may be overpowered?

I was looking at the Grundfos 16S07-8 (10154508) 2 wire, 230v. Looking at the specs and reading the pump curve as well as I could given my well depth and where the pump sits (180ft) this seemed to be a good fit with my pressure tank (86 gallon, 23gallon draw down). I did pull an old well report from when it was drilled:

Hours pumped: 3hr
Pumping Rate: 4gpm
Before pumping: 34 ft
When pumping: 200 ft

I'm imagining that the Zoeller pump may be going bad after only being installed for about 6 months. My well does has some sediment and I imagine that impacts the quality and I was thinking Grundfos being a good brand with a stainless impeller would be an advantage. Is this a good pump? Any comments on any of what I said that i'm completely overlooking?

 

[Reach4]

How quickly is the pressure tank refilled now?

The 10S07-12 would be a better choice, I think.

 

[Sponsor]

 

[justler]

It's taking approximately 13 minutes from the time the pressure switch cuts in to the time it cuts off.

That tells me the current pump is pumping around 1.75gpm (23gallons pressure tank draw down / 13 min). It used to refill in about 1-2 mins.

 

[Valveman]

That pump should be making at least 9 GPM, so something is wrong. Sand can wear the impellers where they won't put out as much as they should. Stainless impellers will not last any longer than plastic when pumping sand. if sand wore out the pump you need to fix the sand problem before wearing out another pump. And as has been said the 10 GPM, 3/4HP is what you need as the 16 GPM pump won't make pressure from that depth.

 

[LLigetfa]

It's taking approximately 13 minutes from the time the pressure switch cuts in to the time it cuts off.

Is this after just a short use test or after using a lot of water? You need to separate the possibility that the water level is being drawn down far enough to put the pump off the curve.
Do you have any additional check valves after the pump? You need to determine if you could have a leak that is being masked by a check valve.

 

[Fitter30]

Heres a pump curve of your pump. If your getting sediment and it's blocking the inlet or wearing the impellers . Pump needs to be pulled, inspected to see whats the problem Any idea how swallow your water level is since 200' is the depth. A different pump level might help. A good well service company that works a lot in your area should know whats going on in your area. This is the parent company of zoeller pump might want to contact them.
https://www.flintandwalling.com/en-na/
http://pumpsizing.flintandwalling.com/PumpSizing/PumpSizing3.aspx

 

[Reach4]

Is this after just a short use test or after using a lot of water? You need to separate the possibility that the water level is being drawn down far enough to put the pump off the curve.
Do you have any additional check valves after the pump? You need to determine if you could have a leak that is being masked by a check valve.

Yeah, two things for justler to do to help diagnose what LLigetfa suspects.

1. post a photo of the pressure switch, pressure gauge, and the pipe coming in from the well.
2. measure the current to the well on one hot wire while the well is pumping. Use a clamp-around ammeter.

 

[LLigetfa]

Hours pumped: 3hr
Pumping Rate: 4gpm
Before pumping: 34 ft
When pumping: 200 ft

Having too large of a pump and a large pressure tank on a slow producing well can be counterproductive. The tank is seen as an additional load on the well. I didn't see mention of casing size to be able to calculate how much storage the casing offers.

Too large a pump can create an upthrust condition on start. If you have extra check valves, they can add to the upthrust. You might need to put a dole valve in the line.

 

[justler]

Is this after just a short use test or after using a lot of water? You need to separate the possibility that the water level is being drawn down far enough to put the pump off the curve.
Do you have any additional check valves after the pump? You need to determine if you could have a leak that is being masked by a check valve.

This is after running the pressure tank down once only in the middle of the day. We only have 2 adults and an infant so water use is low and one person showered for 20 mins in the morning.

Here's the info from from the initial well drilling, looks like they pumped 3 hours, there was water 34ft from the ground/top of well.

It seems to take 13 minutes no mater if water was used a lot or a little prior to emptying the pressure tank.

On top of the well pump is a brass check valve, after that it comes up the poly pipe to a pitless adapter then into the house and a large brass brass T screwed into the A.O. Smith pressure tank. On the T is 1/4" hole where the 40/60 pressure switch is as well as a pressure check valve and a boiler drain valve. It leaves the Pressure tank, goes into CPVC to a sediment filter then a water softener with a Fleck 5600SXT head.

I did turn off the house water after the pressure tank, drained the pressure tank til the pressure switch kicked on and it still took about 13 mins to fill, so no leaks after the pressure tank.

In my thought process, I wouldn't think the problem would be the well draw down as everything worked fine refill wise for about 4-5 months after new pump install. We haven't had a drought or anything.

 

[justler]

Having too large of a pump and a large pressure tank on a slow producing well can be counterproductive. The tank is seen as an additional load on the well. I didn't see mention of casing size to be able to calculate how much storage the casing offers.

Too large a pump can create an upthrust condition on start. If you have extra check valves, they can add to the upthrust. You might need to put a dole valve in the line.

The well casing should be 6". The well report above says "Nominal diameter top casing" - 6. I wouldn't think it would get smaller past the casing?

On the well report, I think they are saying the well refreshes at 4GPM?

 

[justler]

Yeah, two things for justler to do to help diagnose what LLigetfa suspects.

1. post a photo of the pressure switch, pressure gauge, and the pipe coming in from the well.
2. measure the current to the well on one hot wire while the well is pumping. Use a clamp-around ammeter.

Here are the Amp readings on each Leg (9.26 and 8.94) as well as a picture of the pressure tank.

My plan is to drain the pressure tank out when the laundry is done, leave the drain valve open and just make sure the pressure is still reading 38 PSI.

 

[LLigetfa]

On the T is 1/4" hole where the 40/60 pressure switch is as well as a pressure check valve and a boiler drain valve.

Not sure about where you live but a topside check valve is illegal in many states. It can mask a leak between the pump and the tank. If that leak were between the casing and the house, it could suck in contaminated surface water.
I would remove the innards from that check valve and see if it holds pressure. If it does not hold, that suggests you might have a leak. The leak can rob GPM that should be going to the tank.

EDIT: Looking at the pics, I cannot see any check valve. Perhaps you meant to write "pressure relief valve"?

 

[justler]

Not sure about where you live but a topside check valve is illegal in many states. It can mask a leak between the pump and the tank. If that leak were between the casing and the house, it could suck in contaminated surface water.
I would remove the innards from that check valve and see if it holds pressure. If it does not hold, that suggests you might have a leak. The leak can rob GPM that should be going to the tank.

EDIT: Looking at the pics, I cannot see any check valve. Perhaps you meant to write "pressure relief valve"?

I'm sorry, I should have said a pressure gauge and pressure relief valve. There is no check valve except for the brass one screwed in directly above the submersible pump down in the well (which it sounds like shouldn't be there).

 

[LLigetfa]

There is no check valve except for the brass one screwed in directly above the submersible pump down in the well (which it sounds like shouldn't be there).

That one is fine and is considered best practice if the one built into the pump is of questionable quality. By topside, I mean above ground.

 

[Reach4]

Here are the Amp readings on each Leg

That 9.1 amps is a little above the expected "full load" amps of a 2-wire 1hp motor, but less than the "maximum load". I am not sure what to make of that, but I expect that Valveman will be able to draw an inference. This seems not compatible with the water being too deep.

as well as a picture of the pressure tank.

I don't see anything that looks like a check valve, in that photo, to me. That's good.

Not related to any symptom, I also don't see a valve for the water headed for the house. It may be off of the left of the photo.

Do you pump up sand? Valveman was wondering if sand was wearing out the pump.

 

[justler]

That 9.1 amps is a little above the expected "full load" amps of a 2-wire 1hp motor, but less than the "maximum load". I am not sure what to make of that, but I expect that Valveman will be able to draw an inference. This seems not compatible with the water being too deep.


I don't see anything that looks like a check valve, in that photo, to me. That's good.

Not related to any symptom, I also don't see a valve for the water headed for the house. It may be off of the left of the photo.

Do you pump up sand? Valveman was wondering if sand was wearing out the pump.

I'm not sure that it's sand, but it is some kind of sediment. I have a 50/5 micron spun filter installed AFTER the pressure tank.

So this sediment has been in my toilet tank since about 8 months ago (when we moved in), doesn't seem to be accumulating and was there prior to us living here.

This is what the bowl looks like.. there is an orangish ring stain that I think may be iron (was there before we moved in).

Here is my filter that's been installed for about 30 or so days (CW5-BBS cartridge in there)

The filter housing is installed in the proper direction:

 

[Reach4]

Here is my filter that's been installed for about 30 or so days

It looks like sand in the bottom of the clear sump. When you next change that filter, save that sediment in the bottom of the sump for better inspection.

 

[justler]

It looks like sand in the bottom of the clear sump. When you next change that filter, save that sediment in the bottom of the sump for better inspection.

I think it is. I haven't seen this kind of buildup on my filter before. There is a decent sized clump you'll see. Usually it's just the silty stuff sitting with a small amount in the bottom.

 

[Reach4]

So two concerns on the sand. Wearing out the pump, and filtering it out.

Filtering wise, there is more that could be done. Maybe a first filter with a washable pleated cartridge that you could hose off. Or a spin-down filter that is easy to clean first.

For the well, that's harder. With your 6 inch well, a pvc liner is possible.

 

[LLigetfa]

With your 6 inch well, a pvc liner is possible.

If the sediment is coming in above the pump, adding a flow inducer sleeve should help. Slowing down the pump with a dole valve might help as well. That of course is meant as advice for when the pump is producing the GPM it should.