🛁 Marlow Gemini Plus II Bath Pump 0060F88C — 1.5 HP 115V 12.5A Whirlpool Bath Pump with Air Switch & NEMA Cord

The industry-standard high-flow bath pump — variable speed capable, designed for premium whirlpool tubs

♨️ Product Overview

The Gemini Plus II 0060F88C (model NR4A-C) is a 1.5 HP single-speed whirlpool bath pump originally designed by ITT Marlow, later produced by Hydro Air, and now manufactured by Balboa Water Group. This pump is the high-flow workhorse of the Gemini Plus II platform — the pump that became “the choice” of whirlpool bath manufacturers for nearly a decade and set the standard for high-performance jetted bath systems.

The Gemini Plus II differs from the Vico WOW platform in several important ways. First, it supports an optional Digital Variable Speed Control Kit (the Titan or Gemini Bath Control, sold separately) for adjustable jet intensity. Second, it uses a different physical form factor — 12-11/16″ × 5-11/16″ × 7-3/4″ — more compact in length but taller than the WOW series.

The pump features a self-draining volute, built-in air switch, NEMA power cord, and 1-1/2″ Male Buttress Thread (MBT) connections. At 12.5A, it draws slightly less current than the WOW 1074002 (13A) while delivering comparable 1.5 HP performance. The 0060F88C carries both UL and CSA certification and the same less than 0.1% failure rate that Balboa claims across its bath pump lineup. Union fittings are sold separately.

⚠️ NOTE: This is a whirlpool bath pump for jetted bathtubs. It is NOT a hot tub/spa jet pump or circulation pump.

ℹ️ BRAND HISTORY: This pump has been sold under three brand names over the years: ITT Marlow → Hydro Air → Balboa Water Group. All refer to the same Gemini Plus II platform. If your old pump says “Marlow” or “Hydro Air,” this is the current replacement.

⭐ Key Features

• ✅ 1.5 HP Single-Speed Motor — 115V / 60Hz / 12.5A — plug-in ready
• ✅ Variable Speed Capable — Optional Titan/Gemini Bath Control for adjustable jet intensity (sold separately)
• ✅ Built-In Air Switch — Pneumatic on/off via deck button (button/hose sold separately)
• ✅ NEMA Power Cord Included — 3-prong grounded plug — standard 115V outlet
• ✅ Self-Draining Volute — Hygienic design empties after each use
• ✅ 1-1/2″ Male Buttress Thread (MBT) — Both suction and discharge
• ✅ Compact Design — 12-11/16″ × 5-11/16″ × 7-3/4″ — fits tight bath installations
• ✅ Ultra-Quiet Operation — Designed for premium whirlpool environments
• ✅ Less Than 0.1% Failure Rate — Industry-leading Balboa reliability
• ✅ UL and CSA Approved — North American safety certified
• ✅ Replaces All ITT Marlow & Hydro Air Gemini Pumps — One pump covers three brand eras
• ✅ California Title 20 Compliant — Meets energy efficiency standards

⚙️ Technical Specifications

Specification	Value
Manufacturer	Balboa Water Group (formerly Hydro Air / ITT Marlow)
Model Series	Gemini Plus II
Model Number	NR4A-C
Part Number	0060F88C
Alternate Part Number	0060F00C, HA0060F88C
Pump Type	Whirlpool Bath Pump (Front/Top)
Motor Power	1.5 HP
Speed	Single Speed (1-Spd) — variable speed capable with optional controller
Voltage	115V
Frequency	60 Hz
Amperage	12.5A
Frame Size	15 Frame
Suction Style	Bottom
Suction Connection	1-1/2″ Male Buttress Thread (MBT)
Discharge Style	Center
Discharge Connection	1-1/2″ Male Buttress Thread (MBT)
Drain Plug	None (self-draining volute)
Dimensions (L × W × H)	12-11/16″ × 5-11/16″ × 7-3/4″
Discharge Height	7-3/4″
Unions	Sold separately (1-1/2″)
Power Cord	NEMA cord with 3-prong grounded plug (included)
Air Switch	Built-in on/off (included — button and hose sold separately)
UPC	852673919345
Certifications	UL Listed, CSA Approved
California Title 20	Compliant

⚡ Electrical Requirements

Electrical Spec	Requirement
Supply Voltage	115V
Frequency	60 Hz
Phase	Single Phase
Full Load Amps	12.5A
Recommended Circuit	Dedicated 20A GFCI-protected circuit
Connection	NEMA 3-prong grounded plug (included)

📐 Dimensions & Mounting

Measurement	Value
Length	12-11/16″
Width	5-11/16″
Discharge Height	7-3/4″
Overall Height	7-3/4″

The Gemini Plus II has a different footprint than the Vico WOW series (which is 13.5″ × 4.85″ × 7.2″). The Gemini is slightly shorter in length but taller and wider. Verify your under-tub space dimensions before ordering if switching between platforms.

ℹ️ NOTE: Low-profile pump versions are NOT available in the Gemini Plus II platform.

🔩 Plumbing Connections

Connection	Size	Type
Suction (Intake)	1-1/2″	Male Buttress Thread (MBT) — Bottom
Discharge (Output)	1-1/2″	Male Buttress Thread (MBT) — Center

The inlet and outlet have external buttress threads for use with industry-standard whirlpool bath union fittings. Unions are sold separately.

Compatible Union Fittings (sold separately):

Part Number	Description
400-4060	1-1/2″ FBT pump union
400-4200	1-1/2″ FBT pump union
92065	1-1/2″ pump union

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🎛️ Variable Speed Capability

The Gemini Plus II platform supports optional variable speed control — a feature unique to the Gemini platform that the Vico WOW does not offer.

How it works: The Gemini Plus II motor is designed to work with the Titan Bath Control or Gemini Bath Control (sold separately). When connected, this external controller allows the user to adjust jet intensity from gentle to full power via a topside keypad — instead of the simple on/off of the air switch.

What you need for variable speed:

• This pump (0060F88C) — or the no-switch version (0059F88C)
• Titan or Gemini Bath Control (sold separately)
• Compatible topside keypad

Without the variable speed controller: The pump operates as a standard single-speed on/off bath pump via the built-in air switch, exactly like the Vico WOW pumps.

ℹ️ NOTE: The variable speed option is NOT included with this pump. The 0060F88C operates as a standard single-speed pump with air switch out of the box.

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🔄 Part Number Cross-Reference

0060F88C vs 0059F88C — What’s the Difference?

| Part Number | HP | Amps | Air Switch | Notes | |—|—|—|—|—|—| | 0060F88C (this pump) | 1.5 HP | 12.5A | ✅ Yes — built-in | Variable speed capable | | 0059F88C | 1.5 HP | 12.5A | ❌ No | Variable speed capable |

If your tub uses an external electronic control instead of an air button, or if you’re adding a variable speed controller, the 0059F88C (no air switch) may be the appropriate choice.

This Pump Replaces — Primary Cross-Reference

Old Part Number	Notes
0060F88C	Current Balboa/Hydro Air part number (this pump)
0060F00C	Alternate part number (same pump)
NR4A-C	Hydro Air model designation
NR4-C	Hydro Air model variant
HA0060F88C	Hydro Air prefix variant
0014F88C	Legacy Gemini Plus pump
0045E88C	Legacy bath pump
0065F88CC	Legacy bath pump variant
0059F88C	Same pump without air switch
0059F00C	Same pump without air switch (alternate)
1-00-0221	OEM part number
34-109-1040	Catalog number
A014E88C	Legacy part number
5151-211	OEM part number
NL74620DB	Legacy part number
177025	Alternate model code
E203280	Alternate model code
006OF88C	Variant (letter O vs zero)

Legacy Model Designations Replaced

Old Model	Description
HD10A-C	Early Hydro Air model
R100A-C	ITT Marlow / Hydro Air
R100-C	ITT Marlow / Hydro Air
R125A-C	ITT Marlow / Hydro Air
R150A-C	ITT Marlow / Hydro Air
R150-C	ITT Marlow / Hydro Air
NRU2A-C	Hydro Air
NRU3A-C	Hydro Air
NRU3-C	Hydro Air
NRU4A-C	Hydro Air
NRU4-C	Hydro Air
NR3A-C	Hydro Air

Additional OEM Replacements

Old Part Number	Notes
301353	OEM bath pump
5151-100	OEM bath pump
5151-101	OEM bath pump
5151-102	OEM bath pump
5151-103	OEM bath pump
5151-120	OEM bath pump
5151-121	OEM bath pump
5151-123	OEM bath pump
5151-125	OEM bath pump
0013E00CC	Legacy bath pump
R150-CC	Legacy model variant

⚠️ NOTE ON R150VS11C / 0072E00C: These older variable speed models are obsolete. Replacing them with the 0060F88C requires a new variable speed controller and topside — the old controller is not compatible with the Gemini Plus II motor.

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📊 Gemini Plus II Bath Pump Family

Part Number	Model	HP	Amps	Air Switch
0002F88C	NR1	0.5 HP	See label	✅ Yes
0034F88C	NR2A-C	0.75 HP	See label	✅ Yes
0010F88C	NR3	1.0 HP	See label	✅ Yes
0060F88C	NR4A-C	1.5 HP	12.5A	✅ Yes
0059F88C	NR4-C	1.5 HP	12.5A	❌ No

All Gemini Plus II models share: 115V single speed, 1-1/2″ MBT connections, self-draining volute, UL/CSA listed, and variable speed capability with optional controller. Union fittings are sold separately.

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🛠️ Installation Guide

Before You Begin

1. Verify electrical capacity — 12.5A draw requires a dedicated 20A GFCI-protected circuit (recommended)
2. Disconnect power — Unplug the old bath pump before any work
3. Access the pump — Remove the access panel beneath the whirlpool tub
4. Note the existing layout — Take photos before disconnecting anything

Installation Steps

1. Disconnect the old pump — Unplug the power cord, disconnect unions, and remove the pump
2. Position the new Gemini Plus II — Place in the mounting location beneath the tub. Verify dimensions (12-11/16″ × 5-11/16″ × 7-3/4″) fit your space
3. Connect the plumbing — Use 1-1/2″ union fittings (sold separately) to connect suction (bottom) and discharge (center) to existing plumbing
4. Hand-tighten unions — Then snug with a wrench. Do not overtighten
5. Connect the air hose — Run the pneumatic air hose from the tub deck button to the air switch port
6. Fill the tub — Ensure water covers all jets before powering on
7. Plug in the pump — Connect the NEMA cord to a GFCI-protected 115V outlet
8. Test operation — Press the air button to toggle the pump on. Verify water flows through all jets

Important Installation Notes

⚠️ Never run the pump dry — always fill the tub above the jet level before activating

⚠️ The outlet must be GFCI-protected per NEC requirements

⚠️ Low-profile pump versions are NOT available for the Gemini Plus II

⚠️ If switching from a Vico WOW pump, verify the Gemini Plus II dimensions fit your mounting space

⚠️ If the motor doesn’t start when plugged in, the air switch may be in the “off” position — press the air button

⚠️ Union fittings are sold separately — verify you have compatible 1-1/2″ unions before installation

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🔧 Maintenance Guide

Routine Maintenance:

Task	Frequency	Notes
Inspect for leaks	Monthly	Check unions and pump body
Check union tightness	Quarterly	Hand-tighten if loosened
Clean tub jets	Monthly	Remove and clean jet inserts
Flush plumbing lines	Monthly	Run pump with clean water after bath products
Verify air switch function	Monthly	Confirm on/off toggle responds properly
Inspect power cord	Quarterly	Check for damage or exposed wire

Warning Signs — Replace Pump If:

• Unusual noise (grinding, screeching, or loud humming)
• Motor doesn’t start when air switch is toggled
• Water leaking from pump body (not unions)
• Reduced jet flow despite clean jets
• Motor trips GFCI breaker repeatedly
• Burning smell from motor area

🎯 Ideal Applications

Application	Suitability	Notes
🛁 Large whirlpool / jetted bathtub	✅ Yes — Primary Use	High-flow design for premium tubs
🛁 Replacing ITT Marlow bath pump	✅ Yes	Direct replacement for all Marlow Gemini models
🛁 Replacing Hydro Air NR / NRU series	✅ Yes	Direct cross-reference for all HD, R, NR, NRU models
🛁 Variable speed whirlpool system	✅ Yes	With optional Titan/Gemini Bath Control
🛁 Replacing failed 12.5A bath pump	✅ Yes	Match amperage for correct replacement
♨️ Hot tub jet pump	❌ No	Not designed for continuous hot tub use
♨️ Spa circulation pump	❌ No	This is a bath jet pump, not a circ pump

❓ Frequently Asked Questions

Q: What’s the difference between the Gemini Plus II and the Vico WOW? A: Different pump platforms from the same parent company (Balboa Water Group). Key differences: the Gemini Plus II supports optional variable speed control and has a different physical form factor (12-11/16″ × 5-11/16″ × 7-3/4″ vs the WOW’s 13.5″ × 4.85″ × 7.2″). Both are excellent bath pumps with similar reliability. Union fittings are sold separately for both platforms.

Q: My pump says “ITT Marlow” or “Hydro Air” — is this the right replacement? A: Yes. The Gemini Plus II has been manufactured under three brand names over the years: ITT Marlow → Hydro Air → Balboa Water Group. The 0060F88C is the current production replacement for all Marlow and Hydro Air Gemini bath pumps.

Q: Does this pump include union fittings? A: No — union fittings are sold separately. Compatible unions include 400-4060, 400-4200, and 92065 (1-1/2″ FBT). If your existing unions are in good condition, you can reuse them with the new pump.

Q: What is the variable speed option? A: The Gemini Plus II motor supports adjustable speed control when paired with the Titan Bath Control or Gemini Bath Control (sold separately). This lets users adjust jet intensity from gentle to full power via a topside keypad. Without the controller, the pump operates as a standard on/off single-speed pump.

Q: What’s the difference between 0060F88C and 0059F88C? A: The 0060F88C includes a built-in air switch. The 0059F88C is the same pump without the air switch. Choose the 0060F88C for pneumatic air button control; choose the 0059F88C if using an external electronic controller.

Q: Do I need a 20A circuit? A: At 12.5A, this pump is right at the NEC 80% continuous load limit for a 15A circuit (12A). A dedicated 20A GFCI-protected circuit is strongly recommended for reliable operation.

Q: Is this pump discontinued? A: Some retailers list the original 0060F88C as discontinued and offer replacements. However, Spa Parts Plus and other authorized Balboa distributors continue to list it as available. The Gemini Plus II platform remains in production by Balboa Water Group.

🏆 Why Choose the Gemini Plus II 0060F88C

• ✅ Variable Speed Capable — Adjustable jet intensity with optional controller
• ✅ 1.5 HP / 12.5A — Strong performance with slightly lower amperage than the WOW 1074002
• ✅ Industry Standard — “The choice” of whirlpool manufacturers for nearly a decade
• ✅ Less Than 0.1% Failure Rate — Exceptional Balboa reliability
• ✅ Ultra-Quiet Operation — Premium bath experience
• ✅ Self-Draining Volute — Hygienic design prevents stagnant water
• ✅ Three Generations Compatible — Replaces all ITT Marlow, Hydro Air, and Balboa Gemini pumps
• ✅ California Title 20 Compliant — Meets energy efficiency standards
• ✅ Plug-In Ready — NEMA cord with built-in air switch
• ✅ UL and CSA Approved — North American safety certified

🤝 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 in USD
• ✅ Full warranty support
• ✅ Hassle-free returns
• ✅ Variable speed controllers and accessories available
• ✅ Dedicated customer service team

✨ Summary

The Marlow/Balboa Gemini Plus II 0060F88C (model NR4A-C) is a 1.5 HP, 115V, 12.5A single-speed whirlpool bath pump that set the industry standard for high-flow jetted bath systems. Features include self-draining volute, built-in air switch, NEMA power cord, and 1-1/2″ MBT connections (union fittings sold separately). Supports optional variable speed control via the Titan/Gemini Bath Control. Compact 12-11/16″ × 5-11/16″ × 7-3/4″ form factor. UL and CSA approved with less than 0.1% failure rate. Replaces all ITT Marlow, Hydro Air, and Balboa Gemini bath pumps including HD10A-C, R100A-C, R150A-C, NRU3A-C, NRU4A-C, and 30+ additional part numbers. Requires a dedicated 20A GFCI-protected circuit. Order from Parts4Tubs for fast shipping and expert support.