1. Introduction
This manual provides essential information for the safe and efficient installation, operation, and maintenance of your Amtrol RP-25HP Water Pressure Booster System. Please read this manual thoroughly before installation and operation to ensure proper use and to prevent potential hazards or damage.
The Amtrol RP-25HP is designed to increase water pressure in residential or commercial water systems where additional pressure is required. It is a high-performance, whole-house pressure boosting system, pre-assembled with a low-suction cutoff, thermal overload protection, and a built-in junction box. The integrated pressure tank helps reduce pump cycling, improving motor life and efficiency.
2. Safety Information
WARNING: Failure to follow these safety instructions could result in serious injury, death, or property damage.
- Always disconnect power before servicing the unit.
- Installation must comply with all local plumbing and electrical codes.
- This system is not to be used as part of a well system unless a large storage tank is provided.
- Ensure the system is installed in a location protected from freezing temperatures.
- Do not operate the pump dry. Ensure the water supply is connected and flowing before starting.
- The system contains electrical components. Keep away from water and moisture during operation.
- Only qualified personnel should perform electrical connections.
3. System Components
The Amtrol RP-25HP system includes the following key components:
- Booster Pump Assembly
- Pressure Tank
- Pressure Switch
- Low-Suction Cutoff
- Built-in Junction Box
- Thermal Overload Protection

Figure 1: Overview of the Amtrol RP-25HP Water Pressure Booster System. This image shows the compact design of the booster pump and integrated pressure tank.
4. Setup and Installation
Proper installation is critical for the performance and longevity of your system. Consult a qualified plumber or electrician if you are unsure about any steps.
4.1. Site Selection
- Install the system in a dry, well-ventilated area.
- Ensure the ambient temperature remains above freezing (32°F / 0°C).
- Choose a location with easy access for maintenance and service.
- Mount on a solid, level surface to minimize vibration and noise.
4.2. Plumbing Connections
- Connect the incoming water supply to the 1-1/4" inlet pipe.
- Connect the outgoing water line to the 1" outlet pipe.
- Use appropriate pipe fittings and sealants to ensure leak-free connections.
- Install shut-off valves on both the inlet and outlet lines for ease of maintenance.
- Ensure all connections are tight but do not overtighten.
4.3. Electrical Connections
WARNING: Electrical work should only be performed by a qualified electrician.
- Verify the power supply voltage matches the system requirements (115V or 230V).
- Connect the system to a dedicated, properly fused electrical circuit.
- Ensure proper grounding according to local electrical codes.
- The built-in junction box simplifies wiring; follow the wiring diagram provided inside the junction box cover.
5. Operating Instructions
5.1. Initial Startup
- Ensure all plumbing connections are secure and leak-free.
- Open the inlet shut-off valve to allow water to fill the system.
- Open a faucet downstream of the booster system to purge air from the lines. Close the faucet once water flows steadily.
- Restore electrical power to the unit. The pump should start and build pressure.
- Monitor the pressure gauge to ensure it reaches the desired cut-off pressure (factory set to 60 PSI).
5.2. Pressure Adjustment
The system is factory-set with an ON/OFF pressure of 40/60 PSI and a tank pre-charge of 38 PSI. These settings can be adjusted if necessary.
- To operate with lower water main pressure, the pressure switch and tank pre-charge pressure must be adjusted.
- The minimum operating pressure is 5 PSI.
- Consult the pressure switch manufacturer's instructions for detailed adjustment procedures.
- Always disconnect power before making any adjustments to the pressure switch.
6. Maintenance
Regular maintenance ensures optimal performance and extends the life of your Amtrol RP-25HP system.
6.1. Annual Checks
- Check Pressure Tank Pre-charge: Annually, check the air pre-charge in the pressure tank. Turn off the pump, drain the system pressure, and use an accurate tire gauge to check the air pressure. Adjust if necessary to 2 PSI below the pump's cut-in pressure.
- Inspect for Leaks: Visually inspect all plumbing connections for any signs of leaks. Tighten connections as needed.
- Clean Vents: Ensure any ventilation openings on the motor are clear of debris to prevent overheating.
6.2. Winterization (if applicable)
If the system is in an area prone to freezing and will not be used for an extended period, it must be winterized:
- Disconnect electrical power to the unit.
- Close the inlet and outlet shut-off valves.
- Drain all water from the system by opening drain valves or disconnecting pipes.
- Store the pump in a warm, dry place if possible, or ensure all water is completely removed to prevent freezing damage.
7. Troubleshooting
This section provides solutions to common issues you might encounter with your Amtrol RP-25HP system. For problems not listed here, contact customer support.
| Problem | Possible Cause | Solution |
|---|---|---|
| Pump does not start | No power; tripped breaker; faulty wiring; low-suction cutoff activated. | Check power supply and breaker. Verify wiring. Ensure adequate water supply to prevent low-suction cutoff. |
| Low water pressure | Clogged filter; air in system; incorrect pressure switch settings; undersized pump for demand. | Check and clean filters. Purge air from the system. Adjust pressure switch settings. Consult specifications for flow rate. |
| Pump cycles too frequently | Water leak in system; incorrect pressure tank pre-charge; faulty pressure switch. | Check for leaks in plumbing. Verify and adjust pressure tank pre-charge. Inspect or replace pressure switch. |
| Pump runs continuously | System demand exceeds pump capacity (RP-25 designed to run continuously if demand exceeds 3 GPM); significant leak; pump unable to reach cut-off pressure. | Verify system demand. Check for large leaks. Inspect pump for damage or blockages. |
8. Specifications
| Feature | Detail |
|---|---|
| Model Number | RP-25HP (Part Number: R4004) |
| Flow Range | 3-17 GPM (Gallons Per Minute) |
| Horsepower (H.P.) | 1/2 hp |
| Voltage | 115/230 Volts |
| Inlet Pipe Size | 1-1/4" |
| Outlet Pipe Size | 1" |
| Pre-charge PSI | 38 PSI |
| On/Off PSI | 40/60 PSI (Adjustable) |
| Maximum PSI | 100 PSI |
| Width | 24" |
| Height | 39" |
| Ship Weight | 99 lbs |
| Material | Cast Iron, Stainless Steel |
| Style | Submersible |
9. Warranty and Support
For warranty information and technical support, please refer to the official Amtrol website or contact their customer service department. Keep your purchase receipt as proof of purchase.
Amtrol Customer Service: Please visit www.amtrol.com for contact details and further resources.





