💪 Marlow Gemini Plus II Bath Pump 0059F88C — 1.5 HP 115V 12.5A Whirlpool Bath Pump with NEMA Cord (No Air Switch)

Industry-standard high-flow bath pump for controller-operated whirlpool systems — variable speed capable with optional Titan Bath Control

📋 Product Overview

The Marlow/Balboa Gemini Plus II 0059F88C (model NR4-C) is a 1.5 HP, 115V, 12.5A single-speed whirlpool bath pump designed for high-flow jetted bath systems. Manufactured by Balboa Water Group (formerly Hydro Air / ITT Marlow), the Gemini Plus II set the industry standard for premium whirlpool bath pumps and has been the OEM choice for manufacturers for over a decade.

This is the no air switch version — the 0059F88C comes with a NEMA power cord but does NOT include a built-in air switch. This means it must be used with an external controller, wall switch, or the optional Balboa Titan Bath Control system (part 99774, sold separately). If you need a pump with a built-in air switch for simple on/off operation, order the 0060F88C instead.

The pump features a self-draining volute, 1-1/2″ Male Buttress Thread (MBT) connections, and is variable speed capable when paired with the Titan or Gemini Bath Control (sold separately) for adjustable jet intensity from low to high. At 12.5A, it delivers powerful 1.5 HP performance for larger jetted bathtubs with 8 or more jets. The 0059F88C carries both UL and CSA certification with less than 0.1% failure rate and is California Title 20 Compliant.

⚠️ CRITICAL: NO AIR SWITCH — This pump will run continuously when plugged in unless controlled by an external switch or controller. Do NOT plug directly into an outlet without a control device. If you need simple air button on/off operation, order the 0060F88C (with air switch) instead.

⚠️ THIS IS A WHIRLPOOL BATH PUMP — designed for jetted bathtubs only. Not intended for continuous hot tub/spa circulation use.

✨ Key Features

• ✅ 1.5 HP Single-Speed Motor — 115V / 60Hz / 12.5A — high-flow performance for premium jetted baths
• ✅ NEMA Power Cord Included — Plug-in ready (external controller or switch required)
• ✅ Variable Speed Capable — Optional Titan/Gemini Bath Control (part 99774) for adjustable jet intensity from low to high
• ✅ No Air Switch — Designed for controller-operated systems, wall switches, or timer-based installations
• ✅ Self-Draining Volute — Water drains automatically when pump turns off
• ✅ 1-1/2″ MBT Connections — Standard Male Buttress Thread (measures 2-7/16″ OD) — bottom suction, center discharge
• ✅ UL & CSA Approved — Less than 0.1% failure rate, California Title 20 Compliant
• ✅ Legacy Brand Trust — Successor to ITT Marlow and Hydro Air — the original premium bath pump brand
• ✅ Compact Form Factor — 12-11/16″ × 5-11/16″ × 7-3/4″ — fits most under-tub equipment bays
• ✅ 1-Year Manufacturer Warranty — Backed by Balboa Water Group

⚙️ Technical Specifications

Specification	Value
Manufacturer	Balboa Water Group (formerly Hydro Air / ITT Marlow)
Part Number	0059F88C
Model	NR4-C (Gemini Plus II)
Pump Type	Whirlpool bath pump (front/top wet end)
Motor Power	1.5 HP
Speed	Single speed (variable speed with optional controller)
Voltage	115V (110-120V)
Frequency	60 Hz
Amperage	12.5A
Air Switch	❌ Not included — requires external controller
NEMA Cord	✅ Included
Suction Port	1-1/2″ MBT — bottom (measures 2-7/16″ OD)
Discharge Port	1-1/2″ MBT — center (measures 2-7/16″ OD)
Dimensions (L × W × H)	12-11/16″ × 5-11/16″ × 7-3/4″
Self-Draining	Yes
Certifications	UL Approved, CSA Approved
California Title 20	Compliant
Failure Rate	Less than 0.1% (manufacturer claim)
UPC	852673919345
Warranty	1 year manufacturer

🔌 Electrical Requirements

Electrical Spec	Requirement
Supply Voltage	115V (110-120V)
Frequency	60 Hz
Phase	Single
Full Load Amps	12.5A
Minimum Circuit Breaker	20A (NEC 80% rule: 12.5A continuous = 15.6A minimum)
Wire Size (Recommended)	12 AWG

⚠️ IMPORTANT:

All electrical work must be performed by a licensed electrician in accordance with the National Electrical Code (NEC) and local building codes. Whirlpool bath installations require GFCI (Ground Fault Circuit Interrupter) protection. A 20A dedicated circuit is required — a 15A breaker is NOT sufficient for this pump’s 12.5A continuous draw. Do not share circuit with other appliances.

⚠️ 0059F88C vs 0060F88C — Which Do You Need?

This is the most important decision when ordering a Gemini Plus II pump:

Feature	0059F88C (this pump)	0060F88C
Air Switch	❌ NO air switch	✅ Built-in air switch
NEMA Cord	✅ Included	✅ Included
Control Method	External controller, wall switch, or Titan Bath Control required	Air button (sold separately) — press to toggle on/off
Variable Speed	✅ With Titan Bath Control (99774)	✅ With Titan Bath Control (99774)
Single-Speed Use	Runs when power is applied — needs external switch to stop	Air button toggles on/off
Motor & Specs	Identical — 1.5 HP, 115V, 12.5A	Identical — 1.5 HP, 115V, 12.5A
Dimensions	12-11/16″ × 5-11/16″ × 7-3/4″	12-11/16″ × 5-11/16″ × 7-3/4″
Best For	Titan controller systems, wall switch systems, timer-operated tubs	Simple air button on/off operation

Choose 0059F88C (this pump) if:

• Your tub uses a Titan or Gemini Bath Control for variable speed operation
• Your tub has a wall switch, electronic keypad, or timer that controls the pump
• You are replacing an existing 0059F88C or 0059F00C (no air switch) pump
• You want to add the Titan Bath Control (99774) for variable speed capability

Choose 0060F88C instead if:

• You want a simple air button on/off system
• Your existing pump has a built-in air switch
• You don’t need variable speed control

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🔗 Compatibility & Cross-Reference Guide

Direct Replacement For:

Part Number	Brand / Model	Notes
0059F88C	Balboa / Marlow Gemini Plus II	Current model (no air switch)
0059F00C	Balboa / Marlow Gemini Plus II	Earlier version (no air switch)
0059F00CJ	Balboa / Marlow Gemini Plus II	Earlier version variant
0080E88C	Balboa / Marlow	Legacy replacement
0013F88C	Balboa / Marlow	Legacy replacement
0033F88C	Balboa / Marlow	Legacy replacement
0035F88C	Balboa / Marlow	Legacy replacement
NR2-C	Hydro Air / Marlow	Legacy model designation
NR4-C	Balboa / Marlow	Current model designation

Extended Cross-Reference (Legacy Part Numbers):

The Gemini Plus II replaced many legacy bath pump models as the platform was consolidated under Balboa Water Group. The following part numbers from the broader Gemini Plus II family may cross-reference to either 0059F88C (no switch) or 0060F88C (with switch) — verify air switch requirement before ordering:

Part Number	Description
HD10A-C	Hydro Air legacy
R100A-C / R100-C	Gemini legacy (0.5-0.75 HP)
R125A-C	Gemini legacy (1.0 HP)
R150A-C / R150-C	Gemini legacy (1.5 HP)
NRU2A-C / NRU2-C	Gemini Plus legacy
NRU3A-C / NRU3-C	Gemini Plus legacy
NRU4A-C / NRU4-C	Gemini Plus legacy
0014F88C	Gemini Plus II legacy
5151-211 series	Balboa/Marlow legacy
A014E88C	Balboa legacy
0045E88C	Balboa legacy
NL74620DB	OEM cross-reference

Plumbing Compatibility:

📍 Suction: 1-1/2" MBT — bottom (measures 2-7/16" OD)
📍 Discharge: 1-1/2" MBT — center (measures 2-7/16" OD)
📍 Unions: Sold separately (1-1/2")

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 Operation

The 0059F88C is variable speed capable — one of the key advantages of the Gemini Plus II platform over the Vico WOW and other bath pumps.

To enable variable speed, you need:

• Balboa Titan Bath Control (part 99774) — sold separately
• This controller allows you to adjust jet intensity from low to high
• Without the controller, the pump operates as single speed only (full power when energized)

⚠️ OBSOLETE CONTROLLER WARNING: If you are replacing an older R150VS11C or 0072E00C variable speed pump, you will need a new controller and topside — the old variable speed controller is not compatible with the Gemini Plus II.

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🛠️ Installation Guide

Step-by-Step Installation:

1. Disconnect power — Turn off circuit breaker. Never work on plumbing with power connected.
2. Disconnect plumbing — Loosen the union fittings on both the suction and discharge connections. Have towels ready for residual water.
3. Remove old pump — Slide the old pump out of position.
4. Position new pump — Place the 0059F88C in the same orientation as the old pump (suction on bottom, discharge in center). Verify clearance — this pump is 12-11/16″ long.
5. Connect plumbing — Use 1-1/2″ union fittings (sold separately) to connect suction (bottom) and discharge (center) to existing plumbing. Hand-tighten unions — do not over-tighten.
6. Connect controller — Wire the pump to your Titan Bath Control, wall switch, or other control device per the controller’s wiring diagram.
7. Plug in NEMA cord — Connect the 3-prong plug to a GFCI-protected outlet on a 20A circuit.
8. Test operation — Activate the pump through your controller or switch. Fill the tub with water BEFORE running the pump.

Installation Notes:

⚠️ DO NOT plug in without a control device — this pump has no air switch and will run continuously when power is applied

⚠️ Never run the pump dry — always ensure water is above the jet level before activating

⚠️ Pump must be installed below water level (flooded suction) for proper operation

⚠️ Ensure proper grounding and GFCI protection per NEC requirements

⚠️ A 20A dedicated circuit is required — 15A is NOT sufficient for 12.5A continuous draw

⚠️ 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
Check for leaks	Monthly	Around seal plate and union connections
Inspect unions	Monthly	Tighten if needed — do not over-tighten
Check motor vents	Quarterly	Keep clear of debris for proper cooling
Inspect NEMA cord	Quarterly	Look for damage, cracking, or discoloration
Check amperage	Annually	Should read approximately 12.5A under load

Warning Signs — Replace Pump If:

• Unusual noise (grinding, screeching, or humming without rotation)
• Water leaking from the seal plate area
• Motor trips the circuit breaker repeatedly
• Reduced water flow or jet pressure
• Motor overheating or burning smell

Seal Replacement:

📍 Seal Kit: Part 6015200 (Gemini Plus II, 1/2" shaft)
⚠️ Replace seal at first sign of leakage from the seal plate area

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🏭 Brand History

The Gemini Plus II has a long lineage as the premium bath pump platform:

Era	Brand	Notes
Original	ITT Marlow	Created the Gemini bath pump platform
Acquired by	Hydro Air	Continued Gemini Plus development
Current	Balboa Water Group	Manufactures the Gemini Plus II today

This brand heritage means a vast number of legacy part numbers exist across all three brand eras — all now consolidated under the Gemini Plus II platform. The 0059F88C (NR4-C) is the current production model without air switch.

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🎯 Ideal Applications

Application	Suitability	Notes
♨️ Controller-operated whirlpool bath	✅ Yes	Primary intended use
♨️ Titan Bath Control variable speed system	✅ Yes	Adjustable jet intensity
🛁 Wall switch or timer-operated jetted tub	✅ Yes	External on/off control
♨️ Simple air button on/off bathtub	❌ No — use 0060F88C	This pump has no air switch
♨️ Hot tub / spa jet pump	❌ No	Not designed for continuous hot tub use

❓ Frequently Asked Questions

Q: What is the difference between 0059F88C and 0060F88C? A: The 0059F88C does NOT have an air switch — it needs an external controller, wall switch, or timer to turn on/off. The 0060F88C has a built-in air switch — it uses an air button for simple on/off operation. All other specs (1.5 HP, 12.5A, dimensions) are identical.

Q: Can I plug this pump directly into an outlet? A: No — not without a control device. This pump has no air switch and will run continuously when plugged in. You must use a Titan Bath Control, wall switch, electronic keypad, or other control method.

Q: What is the Titan Bath Control? A: The Balboa Titan Bath Control (part 99774) is a variable speed controller sold separately. When paired with the 0059F88C, it allows you to adjust jet intensity from low to high instead of just on/off.

Q: What horsepower is this pump? A: 1.5 HP at 12.5A, 115V / 60Hz.

Q: Does this pump include unions? 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.

Q: What circuit breaker do I need? A: A 20A dedicated GFCI-protected circuit is required. Per the NEC 80% rule, a 15A breaker is insufficient for this pump’s 12.5A continuous draw (12.5A × 80% rule = requires 15.6A minimum capacity).

Q: Does this replace older Marlow and Hydro Air pumps? A: Yes — the Gemini Plus II 0059F88C replaces all legacy Marlow, Hydro Air, and earlier Balboa bath pumps including the NR2-C, NRU series, R100/R125/R150 series, HD10A-C, and 5151-xxx series.

Q: Will this work as a replacement for the R150VS11C variable speed pump? A: The 0059F88C replaces the R150VS11C pump itself, but the old variable speed controller is NOT compatible. You will need a new Titan Bath Control (99774) and topside to restore variable speed functionality.

Q: What voltage does this pump require? A: 115V / 60Hz (110-120V). Plugs into a standard GFCI-protected outlet on a 20A circuit.

Q: Do I need a GFCI breaker? A: Yes — GFCI protection is required by the National Electrical Code (NEC) for all whirlpool bath and spa installations.

🏆 Why Choose the Gemini Plus II 0059F88C

• ✅ Variable Speed Capable — Adjustable jet intensity with optional Titan Bath Control
• ✅ 1.5 HP / 12.5A — Strong performance for large jetted bathtubs
• ✅ Industry-Standard Platform — The OEM choice of bath manufacturers for over a decade
• ✅ Massive Cross-Reference — Replaces dozens of legacy Marlow, Hydro Air, and Balboa part numbers
• ✅ Less Than 0.1% Failure Rate — Proven reliability from Balboa Water Group
• ✅ California Title 20 Compliant — Meets energy efficiency standards
• ✅ UL & CSA Approved — Meets North American safety standards
• ✅ 1-Year Manufacturer Warranty — Backed by Balboa Water Group

🤝 Why Buy From Parts4Tubs

• ✅ Fast shipping across the United States
• ✅ Expert advice from spa and hot tub specialists
• ✅ Competitive pricing
• ✅ Full warranty support
• ✅ Hassle-free returns
• ✅ Union fittings, seal kits, and Titan Bath Controls available
• ✅ Dedicated customer service team

⭐ Summary

The Marlow/Balboa Gemini Plus II 0059F88C (model NR4-C) is a 1.5 HP, 115V, 12.5A single-speed whirlpool bath pump without air switch — designed for controller-operated, wall switch, or Titan Bath Control variable speed installations. Features self-draining volute, 1-1/2″ MBT connections (union fittings sold separately), and NEMA power cord. Replaces all legacy Marlow, Hydro Air, and Balboa Gemini series pumps. UL & CSA approved with less than 0.1% failure rate. Requires 20A dedicated circuit. Order today from Parts4Tubs for fast US shipping and expert support.