One measurement decides most of this, and it is not the size of the house. It is how far down the water sits.
Get that number first and the choice narrows to a couple of models. Skip it and you can spend a long time comparing pumps that were never going to work.
How Do You Choose a Well Pump?
Start with depth to water, because it decides the type before anything else. Under about 25 feet a shallow well jet pump works, and deeper than that needs a deep well jet pump or a submersible. Flow and pressure then narrow it to a model.
Key Takeaways
- Depth to water picks the type, everything else picks the model.
- Suction physics caps shallow jet pumps near 25 feet.
- Size flow from fixtures, not from square footage.
- Read flow at your real depth, never at zero head.
- Set a submersible above the sediment, not near the bottom.
Matching Type to Depth
| Depth to water | Pump type | Where it sits |
|---|---|---|
| Under 25 ft | Shallow well jet | Above ground |
| 25 to 110 ft | Deep well jet | Above ground, two pipes |
| Any depth | Submersible | In the well, below water |
| Cistern or tank | Shallow well or transfer | Above ground |
The 25 foot line is physics rather than a manufacturer’s preference. Atmospheric pressure is what actually pushes water up a suction pipe, and it runs out of ability at around that depth no matter how powerful the motor is.
Working Out the Flow You Need
Household demand is usually estimated by counting fixtures rather than by the size of the house, and a typical home lands somewhere around 8 to 12 gallons per minute at peak.
The number that matters is what the pump delivers at your depth, not the figure on the carton, which is measured with no lift at all. Our guide to reading a pump curve covers finding that, and well construction generally is described by the USGS.
Jet or Submersible?
- Jet pump: above ground, easy to reach, needs priming.
- Submersible: in the well, quiet, never needs priming.
- Servicing: jet is minutes, submersible means pulling the well.
- Noise: a jet pump runs where you can hear it.
- Depth: only a submersible ignores the suction limit.
For shallow water the jet pump is often the better buy purely because you can reach it. Our shallow well jet pump guide covers that case, and the submersible well pump guide covers the other.
The Parts That Come With the Decision
A pump is only part of the order. Every well system needs a pressure tank sized for the pump’s flow, a pressure switch set to match, and on a suction pump a foot valve at the bottom of the line.
Undersizing the tank is the most common way a correctly chosen pump gets destroyed, as our well pressure tank guide explains. A submersible also needs the starting equipment covered in our control box guide, and before replacing anything it is worth confirming the old pump is genuinely the problem using our guide to telling whether a well pump is bad.
Frequently Asked Questions
What size pump for a 200 ft well?
A 200 foot well is well beyond suction lift, so it needs a submersible pump rather than a jet pump. Horsepower then follows the depth to water, the flow the house needs and the pressure required at the tank, read off the pump curve. Well depth alone does not pick a horsepower.
Can you have too big of a well pump?
You can have too big a well pump, and oversizing causes real problems rather than just wasting money. A pump that outpaces the well’s yield draws it down and starts sucking air, and one that empties the pressure tank too quickly short cycles. Match the pump to the well, not to ambition.
What is the average GPM of a residential well?
Most residential wells deliver somewhere in the region of 5 to 15 gallons per minute, though yields vary enormously with geology. The well’s own recovery rate sets the ceiling, not the pump, which is why a driller’s yield figure matters more than the pump’s rating when you are sizing a system.
Is a 3/4 hp well pump better than a 1 hp well pump?
A 3/4 hp well pump is better than a 1 hp pump whenever the smaller one meets the duty, because a larger motor draws more current and can outrun the well’s yield. Horsepower is not a quality rating. Choose the smallest pump that delivers the flow you need at your depth.
What is the most common well pump size?
The most common residential well pump sizes sit between 1/2 and 1 hp, with 3/4 hp being a frequent choice for an average household at moderate depth. The right answer still comes from the depth to water, the flow the house needs and the pressure setting, rather than from what is most often sold.
Well Pumps at Ken’s Distributing
Ken’s Distributing supplies jet pumps, submersibles, tanks and switches across the Franklin Electric range and the Monarch water pump range.
Send us the depth to water, the well depth and the number of fixtures in the house, and we will size the pump and the tank together rather than matching the model that came out.