📥 Downloads and Resources

📄 48/56 Frame Executive, EX2 & Viper Pump Instructions (PDF) — Installation guide, wiring instructions, troubleshooting, and exploded parts view

🔧 Waterway Executive 56 Spa Pump (3722021-13) — 5.0 HP 2-Speed 230V

Engineered for powerful hydrotherapy jets with whisper-quiet dual-speed efficiency

💧 Product Overview

The Waterway Executive 56 (Model 3722021-13) is a premium 5.0 HP dual-speed jet pump designed for high-performance hot tub and spa systems. Manufactured by Waterway Plastics in the USA since 1973, the Executive 56 series pairs a purpose-built wet end with a robust 56-frame motor to deliver maximum jet power on high speed (3450 RPM) and efficient, quiet filtration on low speed (1725 RPM).

Featuring a large 2-1/2 inch intake and a 6-1/2 inch diameter wet end, this pump generates superior head pressure and optimized water flow for multi-jet spa configurations. The Executive wet end rotates in 90-degree increments, allowing flexible installation in virtually any equipment compartment. Built with silicone carbide seals, Viton bellows, and a 316 stainless steel seal casing, the 3722021-13 resists corrosion from chlorine, bromine, and salt water systems.

This model features a 2-1/2 inch suction (center) and 2 inch side discharge with Male Buttress Thread (MBT) connections. Unions and power cord are not included and must be purchased separately.

⭐ Key Features

✅ 5.0 HP Dual-Speed Motor — High speed at 3450 RPM for powerful jets; low speed at 1725 RPM for energy-efficient filtration and circulation

✅ 56-Frame Motor Construction — Larger frame delivers added strength, cooler operating temperatures, and longer motor life compared to 48-frame designs

✅ Large 6-1/2 Inch Wet End — Oversized diameter generates higher head pressure for demanding multi-jet spa systems

✅ 2-1/2 Inch Intake — Extra-large suction port improves water flow performance and reduces operational noise

✅ Silicone Carbide Seal with Viton Bellows — PS1100 seal assembly with 316 stainless steel casing provides exceptional corrosion resistance against chlorine, bromine, and salt

✅ Dual Double-Shielded Ball Bearings — Moisture-resistant grease ensures quieter operation and extended bearing life

✅ Split Capacitor (Start and Run) — Reduces energy consumption during operation

✅ Thermal Overload Protection — Automatic motor protection extends the life expectancy of the motor

✅ Four Sets of Insulated Windings — Two-speed motors feature four winding sets for increased efficiency

✅ 90-Degree Wet End Rotation — Discharge position can be rotated every 90 degrees for versatile installation configurations

✅ Made in the USA — Designed, engineered, and manufactured by Waterway Plastics in Oxnard, California

🔩 Technical specifications

⚡ Electrical Requirements

⚠️ IMPORTANT ELECTRICAL SAFETY INFORMATION:

All electrical work must be performed by a licensed electrician in accordance with the National Electrical Code (NEC) and local building codes. Hot tubs and spas require GFCI (Ground Fault Circuit Interrupter) protection. A dedicated circuit is required — do not share with other appliances.

⚠️ 2-SPEED WIRING WARNING: Do NOT wire both speeds to run simultaneously. When removing the power cord from your existing pump, mark your wires for “common,” “high speed,” and “low speed” before disconnecting. The wiring diagram is located on the motor nameplate or terminal cover.

⚠️ VOLTAGE CHECK: Be sure to check the motor voltage on your existing pump, not the voltage supplied to the spa, to determine the correct replacement pump voltage. Applying incorrect voltage will damage the motor and void the warranty.

🔗 Compatibility Guide

Frame and Port Identification

Specification	This Pump
Frame Type	56 Frame
Wet End	6-1/2 inch diameter
Suction (Intake)	2-1/2 inch MBT (center)
Discharge	2 inch MBT (side)
Discharge Position	Side (rotatable every 90 degrees)

How to Identify Your Pump’s Thread Size

Hot tub pump plumbing sizes are nominal — not the actual outside diameter. Measure the outside diameter of the threaded connection to confirm:

Nominal Size	Actual Thread OD
1-1/2 inch	Approximately 2-3/8 inches
2 inches	Approximately 3 inches
2-1/2 inches	Approximately 3-5/8 inches

How to Select the Correct Replacement Pump

Choosing a pump based on Horsepower (HP) alone can lead to selecting the wrong pump. HP ratings on spa pumps may be listed as SPL-HP, BHP, MBHP, RHP, or S-HP, which differ from continuous operating horsepower. Instead, match these specifications from your existing pump:

1. Confirm whether you have a 48-frame or 56-frame motor
2. Match the high-speed amperage rating on the pump label
3. Confirm suction and discharge port sizes
4. Verify voltage (115V vs. 230V)

Alternate Part Numbers and Cross-References

This pump (3722021-13) is also referenced under the following part numbers:

• PF-50-2N22C
• PF-40-2N22M
• 372202113
• 372202A-13
• WW372202113
• WW37220211345
• 1-00-0220
• 5039-511
• 3722021-0T7GDY
• 3722021-0D86
• 4522021-13
• 1-P250E5252024
• 301921
• 3M22021
• 404041
• FP-45-2N22C
• Dynasty 12600

🔧 Parts and fittings for this

Commonly replaced parts

Parts commonly replaced on this item that we stock.

💡 Motor Brand Note: The last letter in the PF- model number (“C” or “M”) indicates the motor brand. “C” references Century/A.O. Smith motors; “M” references U.S. Motors. This does not need to be matched when selecting a replacement — both deliver the same performance.

Compatible Applications

This pump fits a wide range of hot tub and spa brands. It is used as an OEM or replacement pump in spas from multiple manufacturers. Always verify frame type, amperage, and port sizes before ordering.

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🛠️ Installation Requirements

Mounting

Requirement	Specification
Mounting Position	Horizontal — Must be installed below water level (flooded suction)
Base	Solid, level surface with adequate floor drainage
Ventilation	Ensure adequate airflow around motor for cooling
Access	Allow sufficient clearance for maintenance and future pump removal
Moisture Protection	Installation area should be clear of direct water spray

Plumbing Connections

Connection	Size	Type
Suction (Intake)	2-1/2 inches	Male Buttress Thread (MBT) — Center
Discharge	2 inches	Male Buttress Thread (MBT) — Side
Union Type	Waterway tailpiece assemblies recommended	Hand tighten only — do NOT use wrenches

Installation Notes

⚠️ Pump must be installed below water level — this pump is NOT self-priming

⚠️ Never run the pump dry — causes seal damage and may result in scalding hot water buildup

⚠️ Install shut-off valves on both inlet and outlet for future maintenance

⚠️ Hand tighten unions only — do NOT use a wrench or adhesives

⚠️ Use only Teflon tape or sealing compounds approved for use with plastic — do NOT use pipe dope, as some pipe dopes cause stress cracking of plastic parts

⚠️ The wet end discharge can be rotated every 90 degrees by loosening the four motor thru-bolts

⚠️ Ensure proper grounding and bonding per NEC requirements

⚠️ GFCI protection is required by code for all hot tub and spa installations

⚠️ Pressure testing during installation should not exceed 40 PSI

Product Change Notification

Waterway has updated the Executive wet end configuration. The two side drain plug ports have been removed to streamline production. Only the main bottom drain port remains. If side ports are required for your installation, they can be drilled and tapped on-site.

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🔄 Maintenance Guide

Routine Maintenance

Task	Frequency	Notes
Check for leaks	Monthly	Inspect around seal area, unions, and plumbing connections
Inspect unions	Monthly	Hand tighten if needed — never use a wrench
Clean strainer/filter	As needed	Remove debris to maintain proper flow
Check motor amperage	Annually	Should be within 10% of nameplate rating (16.4A high / 4.8A low)
Inspect motor vents	Quarterly	Keep clear of debris for proper cooling airflow
Check mounting security	Quarterly	Tighten mounting if loose to reduce vibration
Inspect for air leaks	As needed	Air bubbles in return lines indicate suction-side air leak

Warning Signs — Replace Pump If:

• Unusual noise (grinding, screeching, or rumbling)
• Water leaking from the shaft seal area
• Motor trips the circuit breaker repeatedly
• Reduced water flow or jet pressure
• Motor overheating or shutting down on thermal protection
• Motor hums but will not start
• Amperage draw exceeds 10% of nameplate rating

Seal Replacement

Specification	Detail
Seal Model	PS1100
Seal Material	Silicone carbide faces, Viton bellows, 316 stainless steel casing
Chemical Resistance	Chlorine, bromine, and salt water

⚠️ Replace the seal at the first sign of water leakage from the seal area. Continued operation with a leaking seal will damage the motor bearings and windings.

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🎯 Ideal Applications

Application	Suitability	Notes
♨️ Hot tub jet pump	Yes	Primary application — delivers powerful jet pressure for multi-jet configurations
♨️ Spa jet pump	Yes	Ideal for high-performance spa systems requiring maximum flow
🛁 Whirlpool bath	Yes	Can be used with whirlpool bath systems if appropriately marked
♨️ Dual-speed filtration	Yes	Low speed provides energy-efficient filtration at 1725 RPM
♨️ Commercial spa systems	Yes	56-frame construction suited for commercial-grade applications

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❓ Frequently Asked Questions

Q: What horsepower is this pump? A: This pump is rated at 5.0 HP. However, it is important to note that hot tub pump HP ratings can vary by rating method (SPL-HP, BHP, etc.). The most reliable way to confirm you are selecting the correct replacement is to match the high-speed amperage (16.4A for this model) and frame size (56 frame) rather than relying solely on the HP number.

Q: Will this fit my hot tub? A: This pump has a 56-frame motor with a 2-1/2 inch suction (center) and 2 inch side discharge using Male Buttress Thread connections. To confirm compatibility, check your existing pump’s frame type, amperage rating, and port sizes. If your current pump is a 48-frame, this pump will NOT be a direct replacement — 48-frame and 56-frame motors have different bolt patterns and physical dimensions.

Q: What voltage does this pump require? A: 230V / 60Hz single phase. All electrical installation must be performed by a licensed electrician. Using incorrect voltage will damage the motor.

Q: Does this pump run on 115V or 230V? A: This specific model (3722021-13) is 230V only. Always verify the voltage on your existing pump’s motor nameplate — check the motor voltage, not the voltage supplied to the spa panel.

Q: Is this a single or dual speed pump? A: This is a dual-speed (2-speed) pump. High speed runs at 3450 RPM (16.4A) for jet operation. Low speed runs at 1725 RPM (4.8A) for filtration and circulation. It can also be wired for single-speed operation if needed.

Q: What size are the ports? A: Suction (intake): 2-1/2 inches MBT (center). Discharge: 2 inches MBT (side). The nominal sizes do not match the actual thread outside diameter — the 2-1/2 inch port measures approximately 3-5/8 inches OD, and the 2 inch port measures approximately 3 inches OD.

Q: Does this pump come with a power cord and unions? A: No. This pump does NOT include a power cord or unions. These must be purchased separately. For 2-speed pumps, a 4-wire AMP cord is typically required.

Q: What warranty is included? A: Waterway provides a manufacturer warranty. Warranty duration may vary — contact Parts4Tubs for current warranty terms and details.

Q: How do I know if my pump needs replacing? A: Signs that your pump needs replacement include unusual noise (grinding, screeching), water leaking from the seal area, reduced jet pressure, the motor repeatedly tripping the breaker, the motor overheating or shutting off, or the motor humming but not starting.

Q: Do I need a GFCI breaker? A: Yes, GFCI (Ground Fault Circuit Interrupter) protection is required by the National Electrical Code (NEC) for all hot tub and spa installations. This is a critical safety requirement.

Q: Can I rotate the discharge direction? A: Yes. The wet end can be rotated every 90 degrees by loosening the four motor thru-bolts. The pump ships with the discharge in the factory default position. This allows the discharge to be oriented at 12, 3, 6, or 9 o’clock positions.

Q: What is the difference between the 3722021-13 and the 3722021-1D? A: Both are 5.0 HP 2-speed Executive 56-frame pumps running at 16.4/4.8 amps on 230V. The difference is the port configuration: the 3722021-13 has a 2-1/2 inch intake and 2 inch discharge, while the 3722021-1D has both intake and discharge at 2 inches.

Q: What does the “C” or “M” in the PF model number mean? A: The last letter indicates the motor brand used. “C” references Century/A.O. Smith brand motors; “M” references U.S. Motors. Both deliver the same performance specifications, and the motor brand does not need to be matched when selecting a replacement.

🏆 Why Choose the Waterway Executive 56 (3722021-13)

✅ Maximum Jet Power — 5.0 HP motor at 16.4 amps delivers powerful hydrotherapy performance for multi-jet spa configurations

✅ Energy-Efficient Dual Speed — Low-speed filtration at 4.8 amps significantly reduces energy costs compared to running at full power

✅ Premium Seal System — Silicone carbide seals with Viton bellows and 316SS casing resist corrosion from chlorine, bromine, and salt systems

✅ Quiet Operation — Dual double-shielded ball bearings with moisture-resistant grease and oversized 2-1/2 inch intake reduce operational noise

✅ Versatile Installation — 90-degree wet end rotation and side discharge design accommodate a wide range of equipment compartment layouts

✅ American Quality — Designed, engineered, and manufactured in the USA by Waterway Plastics in Oxnard, California

🤝 Why Buy From Parts4Tubs

✅ US-based support for American customers

✅ Fast shipping across the United States

✅ Expert advice from spa and hot tub specialists

✅ Competitive pricing

✅ Full warranty support

✅ Hassle-free returns

✅ Replacement seals, unions, and AMP cords available

✨ Summary

The Waterway Executive 56 (3722021-13) is a 5.0 HP dual-speed jet pump built for demanding hot tub and spa applications. Running at 16.4/4.8 amps on 230V with a 56-frame motor, this American-made pump features a large 2-1/2 inch intake, 6-1/2 inch wet end for superior head pressure, and a premium PS1100 seal assembly with silicone carbide, Viton, and 316SS construction. The rotatable wet end, side discharge configuration, and proven Executive series design make it an ideal replacement for high-performance spa systems. Available now at Parts4Tubs with expert support and fast US shipping.

Find the right pump or motor

Enter what is printed on the label of the one you are replacing. Anything that differs is shown with the difference spelled out, so you can judge it for yourself.

EitherComplete pumpMotor only

Make or modelHorsepowerVoltageAny115V230VSpeedAny1-speed2-speedVariable speedAmpsPort size (pumps)Any3/4 in1 in1-1/2 in2 in2-1/2 inFrame (motors)Any48Y48 frame56Y56J56C56 frame

Clear

Port size is the plumbing thread, not the pipe — a 2 inch union measures about 3 inches across the male thread. Amps are compared to within half an amp, since published figures round differently between motor brands. Voltage is never treated as a near miss: a 115V motor is not one step from a 230V supply. Anything whose page does not publish a figure you entered is left out rather than offered with a caveat — search it by name to see it anyway.

Unions and pump cords: pick the union size that matches your pump's ports (see the size chart below), and a 4-wire cord for a 2-speed pump.

Hot Tub Pump Collar & Union Size Chart

Imperial & Metric Specifications

Union Size	Collar Size	Thread OD	Union OD	O-Ring Size
1.5" Female Buttress Thread (FBT)	2.5" / 64mm (Tip to Tip) Measurement	2-1/2" 64mm	2-13/16" 71mm	2-5/16" OD 59mm
2" Female Buttress Thread (FBT)	3.1" / 78mm (Tip to Tip) Measurement	3-1/16" 78mm	3-3/8" 81mm	2-15/16" OD 75mm
2.5" Female Buttress Thread (FBT)	3.6" / 91mm (Tip to Tip) Measurement	3-5/8" 91mm	4-1/4" 108mm	3-7/16" OD 87mm

Important Notes

The union "size" (1.5", 2", 2.5") is nominal and doesn't correspond to any actual measurement.

Collar size is measured from thread tip to thread tip on the pump outlet.

Most hot tub pumps use Female Buttress Thread (FBT) - 98% of applications.

O-ring gaskets may vary between manufacturers - measure your existing gasket for accuracy.

How do I Replace a Hot Tub Pump?

Here's a general step-by-step guide on how to replace a hot tub pump. Keep in mind that the specific steps may vary depending on your hot tub's make and model, so it's essential to consult your hot tub's manual for model-specific instructions. If you're not comfortable with this procedure, it's a good idea to seek professional assistance.

Materials You'll Need:

• Replacement pump
• Screwdriver
• New union O-rings
• A strap wrench, only if a union nut is stuck
• PVC primer and cement, only if you are gluing in new tailpieces

Procedure:

1. Turn Off the Power: Before you begin, ensure the hot tub's power supply is turned off at the circuit breaker or disconnect switch. Safety should always be a priority when working with electrical components.

2. Drain the Hot Tub: If your hot tub is not already empty, you'll need to drain it. Follow your hot tub's manual or manufacturer's instructions for proper draining. (You might not need to do this if you can lock the pump off with the gate valves)

3. Locate the Pump: Identify the location of the existing pump in your hot tub. It's usually located near the equipment area or in a designated pump compartment.

4. Disconnect the Electrical Wiring: Carefully disconnect the electrical wiring from the old pump. This typically involves removing the electrical conduit cover, unscrewing wire nuts, and disconnecting the wires from the terminals. Be sure to note the wire connections or take a picture for reference when connecting the new pump.

5. Disconnect the Plumbing: Depending on your hot tub's plumbing setup, you'll need to disconnect the plumbing connections to the pump. Unscrew the union nuts by hand. If one is stuck, use a strap wrench rather than a pipe wrench, which can crack the nut. Be prepared for some water spillage when disconnecting the plumbing.

6. Remove the Old Pump: Once the electrical and plumbing connections are detached, carefully remove the old pump from its mounting position. Some pumps may be secured with mounting brackets or bolts.

7. Prepare the New Pump: If the new pump is not pre-assembled, you may need to attach fittings, unions, or adapters to match your hot tub's plumbing. Pump unions use buttress threads that seal on an O-ring, so fit new O-rings and hand-tighten the nuts. Do not use thread tape, pipe dope or sealant on them.

8. Mount the New Pump: Position the new pump in the same location as the old one and secure it in place using the mounting brackets or bolts.

9. Reconnect Plumbing: Reconnect the plumbing to the new pump, hand-tightening the union nuts. If you are gluing in new PVC tailpieces, use PVC primer and cement on those joints.

10. Reconnect Electrical Wiring: Reconnect the electrical wiring to the new pump, following the notes or pictures you took earlier. Make sure all wires are properly connected and secure.

11. Turn On the Power: Restore power to the hot tub by switching on the circuit breaker or reconnecting the disconnect switch.

12. Test the Pump: Turn on the hot tub's pump to ensure that it's working correctly. Check for any signs of leaks or irregularities in the plumbing connections.

13. Refill the Hot Tub: Once you've confirmed that the new pump is functioning properly, refill the hot tub with water.

14. Check for Leaks: Inspect the plumbing connections for any leaks. If you find any, turn off the pump, drain the tub again, and reseal the connections as needed.

15. Monitor: Keep an eye on the pump and plumbing for the next few days to ensure everything is functioning correctly and that there are no further issues.

Remember that this is a general guideline, and the specific steps may vary based on your hot tub's design. If you're unsure or uncomfortable with any aspect of this process, please do get in touch, happy to help.

How do I know what size hot tub pump I have?

Determining the size of your hot tub pump is an important step when it comes to maintenance or replacement. To find out the size of your hot tub pump, follow these steps:

1. Check the Manual: The easiest way to determine the size of your hot tub pump is to consult the owner's manual or user documentation that came with your hot tub. The manual typically contains detailed information about the specifications and components of your hot tub, including the pump.

2. Look at the Pump Housing: If you don't have access to the manual or it doesn't provide the information you need, inspect the pump itself. Most hot tub pumps have a label or plate on the pump housing that displays essential details, including the pump's model number, manufacturer, and specifications. You can then send that to me or Google it.

3. Measure the Pump: If the label is missing or damaged, you can measure the pump's dimensions. Measure the diameter of the pump's wet end (the part where the water flows) and the length of the wet end. These measurements can help identify the size and capacity of the pump.

4. Consult the Manufacturer: If you can't find the information on the pump or in the manual, contact the hot tub manufacturer or a reputable dealer. Provide them with your hot tub's model and serial number, and they should be able to identify the correct pump size for your specific hot tub.

5. Online Research: You can also search online using the pump's model number or hot tub's make and model. Many manufacturers provide detailed information about their products on their websites, and you may find specifications for your pump model.

Once you have determined the size and specifications of your hot tub pump, you can proceed with maintenance, repairs, or replacement if necessary. Keep in mind that replacing a hot tub pump with the same size and capacity as the original is crucial to ensure proper water circulation and filtration in your hot tub. If you're unsure about any aspect of this process, get in touch, always happy to help.