Can the RJS-100-PREM well pump keep usable pressure in a deeper well at its 150 ft maximum head?

You need a well setup that stays within that lift and a pressure system matched to the pump’s 30/50 switch; we picked this model for a full review because its 1 HP rating and 150 ft head define the edge of that use case. Measure your actual lift, not just the well depth, because dynamic head is the working lift after friction losses. A wrong choice here can force a rebuild and a return.

How the RJS-100-PREM’s head and pressure settings affect use

The RJS-100-PREM is a shallow-well jet pump, a water-moving pump for surface-mounted systems, with a 1 HP motor, 23 GPM maximum flow rate, and 1 in discharge. Its 150 ft max head is the limit that matters for deeper wells, while the factory-set 30/50 pressure switch and 50 PSI working maximum pressure shape how it cycles at the tap. That is why this question matters for a well pump buyer: maximum head tells you whether the pump can lift water, but usable pressure depends on the whole system, including submergence depth, pipe size, and voltage drop over the run. A 1-1/4 FNPT suction intake and 1 FNPT outlet discharge also mean your plumbing has to match the listed sizes.

For a detailed look at the technical specifications, see our full RJS-100-PREM review.

What to Check Before Buying the RJS-100-PREM

• Measure your actual dynamic head, not only the static water level. Dynamic head is the working lift after friction and elevation losses.
• Confirm your submergence depth stays safe for the intake. Low water can expose the pump to dry running.
• Check your pipe diameter against the 1-1/4 FNPT suction intake and 1 FNPT outlet discharge. Wrong sizes can create friction loss or fit problems.
• Measure voltage at the pump location for a 115 V or 230 V run. Long wire runs can create voltage drop and reduce performance.
• Verify that your pressure switch or controller matches a 30/50 setup. The pump itself does not regulate pressure alone.

Where the RJS-100-PREM Fits Among Deeper-Well Options

RJS-100-PREM suits you if your well is deep enough to need a 150 ft lift limit, but not so demanding that you need more head margin or a different pump style. Buyers with longer runs, lower water levels, or a need for more pressure stability should look at other well pump types instead, especially when the system needs more than a 1 HP surface jet pump can reasonably support. The cast iron casing and volute point to a straightforward utility build, not a stainless-steel package.

You can also view how the RJS-100-PREM compares to others in our dedicated breakdown.

Choose this pump if your measured lift, plumbing sizes, and electrical supply all line up with its listed figures, and if you want a 1 HP option with a 23 GPM rating and a 30/50 switch already set. If your well needs more head reserve or a different control setup, a different pump type is the safer buy.

If you are looking for off-grid options, learn how to run a well pump on solar power.

Reviewed by the Predicament Measures editorial team.