Diagnosing the pressure problem
Attach a $15-$20 pressure gauge (available at hardware stores) to the main water shutoff valve or an exterior hose bib and measure static pressure (with no fixtures running) and dynamic pressure (with multiple fixtures running simultaneously). Static pressure below 40 PSI indicates a low-pressure supply issue -- confirm with the water utility whether this is a known service area issue. Dynamic pressure that drops more than 15-20 PSI from static with two fixtures running indicates either a supply restriction or an undersized supply main. If static pressure is adequate but specific fixtures have low pressure, the issue is local to the fixture, not the supply system.
Booster pump sizing -- PSI and GPM
A residential pressure booster must provide enough flow at the desired outlet pressure to serve the peak simultaneous demand in the home. For a 3-bedroom home with 2.5 baths, peak demand is approximately 10-12 GPM (two showers + kitchen sink). Size the booster pump to deliver at least 10 GPM at 55 PSI outlet. The Rheem RP17461 and comparable systems are rated in these ranges -- verify the pump curve data (GPM at defined PSI points) matches your calculated demand before purchase.
Variable speed vs fixed speed
Variable speed booster pumps (like Rheem's RP17461) use an electronically commutated motor (ECM) that adjusts speed to maintain target pressure regardless of demand level. At low demand (one faucet running), the pump runs slowly and uses 30-50 watts. At full demand, it ramps to full speed. Fixed-speed pumps run at full speed whenever they are on, producing a pressure spike when first activated and running inefficiently at partial demand. Variable speed is the correct choice for most residential applications -- the efficiency difference reduces operating costs by $50-$150 per year depending on pump use frequency.
Contractor installation requirement
Rheem recommends licensed plumber installation for pressure booster systems. The installation requires main shutoff valve isolation, copper or PEX supply line work, electrical connection (dedicated 120V circuit), and proper bypass piping to allow service without shutting off all home water. DIY installation is possible for experienced homeowners but the booster must be properly grounded and the pressure setpoint calibrated correctly -- incorrect setpoint can push system pressure above the supply line's rated working pressure, causing leak risks. Most Rheem distributors require contractor purchase and installation for warranty coverage.