need help choosing new well pump

[Greenmountain]

I'm looking at these two pumps:

Goulds 18GS15422C 18GPM 1.5HP 230V 2 Wire submersible well pump

Grundfos 16S10-10, Material #10159510, 1 Horse Power, 1 Phase, 230 Volts, 4" Dia, 2-Wire, 16 gallon per minute.

anyone have any feedback around one vs the other?
thanks

 

[Reach4]

Would that be for a 4 bathroom house using a well with a 5 inch casing, water level 70 ft down, and the pump set at 140 ft? They are both quality pumps.

Or is that an irrigation pump or what?

 

[Sponsor]

 

[Greenmountain]

2 houses; 3 baths total, 2 kitchens. will be adding irrigation and probably water for horses in future. well is only about 15' deep so pump just sits in the water a little bit up off the bottom of the well (rated at 15gpm+), about 100' vert to upper house and at least 200' horizontal. 1.25" main.

 

[Greenmountain]

just spoke with a local pump guy who says grundfos are terrible... bad spot welds on too thin stainless?

 

[Reach4]

Pumps seem appropriately sized for that -- about 120 ft rise. Are the two houses at about the same elevation?

 

[Greenmountain]

no, it's maybe approx 40' vert between where the main comes in in the lower house vs upper house

 

[Reach4]

40 feet is 17.34 PSI difference. So you would want the lower altitude pressure at at least 45...65 to give 27.66 ... 47.66 PSI in the higher house. Maybe go 50...70 on the lower. I presume the pressure tank and pressure switch will be at the lower house. If those are somewhere lower still, that can cause further considerations.

You always want a pressure tank at the pressure gauge and normally that would have the air precharge set to 2 PSI lower than the switch cut-in pressure. You could have one or more elsewhere, with the precharge adjusted accordingly. Pressure gauges would help set the appropriate precharge for an extra tank not located at the pressure switch. You will want a total of 18 gallons of drawdown or more.

If these houses are not owned by the same owners (or there is a renter), you need to give thoughts about the agreement. Sometimes things become less amicable over time. One participant might later resent the excessive water use by the other, for example.

 

[Valveman]

Nothing wrong with Grundfos. Stainless is thin, but is as good as any with plastic impellers. Installers only like the brand they sell. And a Cycle Stop Valve is a good idea with the varied, multiple uses for water and will also let you use a smaller tank.

 

[Greenmountain]

I'm thinking of eventually adding a secondary pump and pressure tank with check valve for the upper house so that it will have it's own pressure regulation. Not sure exactly what that would mean for sizing the primary pump... I'd assume the primary, submersible pump could be down sized a little if the 2nd house has it's own smaller pump and tank? does that make sense?

 

[Valveman]

About 5 gpm is all a house needs, plus what is needed for irrigation. One pump will run several houses. But it usually makes for better neighbors for each to have their own well and pump.

 

[Reach4]

Not much difference. You could add a pressure regulator for the lower house if the upper house needs more pressure. But I think you should be OK, without that. Maybe make the piping to the upper house a full inch to minimize drop due to flow.

I am not a pro. Just an amateur opinion.

 

[Greenmountain]

just one well, but no lack of water..., would like to provide equal or better pressure at upper house, so a pressure limiter on the lower house could work, although I'm reluctant to push it too high. To get 60psi at upper house, pressure switch in lower house would need to be set at close to 80psi then, then reduced back to 60 for lower house?
so, back to the pumps then... I recall reading that the amperage drop at low flow is better with the Grundfos... so would that then be the better pump if using a CSV? Also, for the short term, water use is fairly low. My shower is rated at 4gpm, so that is the biggest draw at this time, but eventually there will be three bathrooms, two kitchens, laundry, irrigation, etc...

 

[Reach4]

80 PSI is considered the max for a residence before needing a regulator.

 

[Valveman]

If you need 80 PSI a the upper house the CSV will need to be set at 80, and use a 70/90 pressure switch. Then just use a pressure regulator at the lower house set at 60 PSI. With 2 houses and a 70/90 pressure switch you really need about a 20 gallon size pressure tank to use with a CSV.

Without a CSV I would use two of the 86 gallon size tanks installed together at the same location as the pressure switch.

 

[Craigpump]

Your pump man is selling you what he stocks and can buy at the best discounts, today Goulds tomorrow Red Jacket, next year Franklin.

If you took a Grundfos pump apart, you'd be amazed at how well they are made. I consider Grundfos to be the Lexus of pumps.