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ITT Marlow Gemini Plus R100A-C Pump Replacement | 1 HP 120V Air Switch

Regular price $259.99 USD
Regular price $319.99 USD Sale price $259.99 USD
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๐Ÿ“ž Need Help? Call or Text (951) 897-1878 Before Ordering
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Restore strong, dependable whirlpool performance with the ITT Marlow Gemini Plus R100A-C Whirlpool Pump Replacement. This 1 HP, 120V bath pump is designed as a replacement for discontinued Gemini Plus and Hydro Air whirlpool pump applications that use a built-in pneumatic air switch.

The R100A-C is a practical solution for homeowners, technicians, and repair professionals replacing an older ITT Marlow or Gemini Plus pump without rebuilding the entire whirlpool system. Its compact bath-pump design, integrated air switch, and included power cord help simplify installation while preserving the original on-and-off operation of the tub.

Why Choose the R100A-C Gemini Plus Pump?

  • Replacement for discontinued ITT Marlow pumps: Designed for many older Gemini Plus and Hydro Air whirlpool bath systems where the original pump is no longer available.
  • 1 HP performance: Provides dependable water circulation and strong jet action for compatible whirlpool bathtubs.
  • 120V operation: Built for standard residential whirlpool bath electrical systems.
  • Built-in air switch: Allows the pump to operate with an existing pneumatic air button when properly connected.
  • Power cord included: Arrives with a factory-installed cord for a cleaner, more convenient installation.
  • Compact bath-pump design: Engineered for whirlpool tubs where space inside the equipment cavity may be limited.
  • Expert replacement support: Whirly Bros can help compare your original pump label, amperage, plumbing orientation, and control method before ordering.

R100A-C Pump Specifications

Model R100A-C
Brand Family ITT Marlow / Gemini Plus / Hydro Air
Application Whirlpool bathtub and jetted tub pump replacement
Motor Rating 1 HP
Voltage 120V
Frequency 50/60 Hz
Amperage 8.5A
Speed Single-speed
Control Built-in pneumatic air switch
Power Cord Included

What Is Included?

  • R100A-C 1 HP whirlpool bath pump
  • Built-in pneumatic air switch
  • Factory-installed power cord
  • Replacement connection components as shown in the product images

Compatibility and Fitment

The R100A-C is commonly used as a replacement for older ITT Marlow Gemini Plus, Hydro Air, and related whirlpool bath pumps with similar electrical specifications, plumbing orientation, and air-switch operation.

Because manufacturers often used different pump configurations across tub models and production years, the model number alone should not be the only factor used to confirm compatibility.

Before ordering, compare the following information from your original pump:

  • Original model and part number
  • Voltage and amperage
  • Horsepower rating
  • Suction and discharge position
  • Plumbing connection size
  • Built-in air switch or external control configuration
  • Available installation space

Important Installation Notes

Installation should be performed by a qualified technician or a person familiar with whirlpool bath electrical and plumbing systems. Always disconnect electrical power before servicing the tub.

Do not operate the pump without water. Running a whirlpool bath pump dry may damage the seal, impeller, or motor assembly.

Replacement pumps may have minor differences in housing shape, cord position, or plumbing alignment compared with an older discontinued pump. Small plumbing adjustments may occasionally be required depending on the original installation.

Frequently Asked Questions

Is the original ITT Marlow R100A-C discontinued?

Many original ITT Marlow and Gemini Plus bath pumps are no longer produced under their original labels. This pump is offered as a replacement solution for compatible R100A-C applications.

Does this pump include an air switch?

Yes. The pump includes a built-in pneumatic air switch designed to work with a compatible air button and air tubing.

Does the R100A-C include a power cord?

Yes. A factory-installed power cord is included.

Is this pump variable-speed?

No. This configuration is intended for single-speed operation. Variable-speed systems may require a different pump and control package.

Can this replace every Gemini Plus pump?

No. Gemini Plus pumps were produced in several horsepower ratings, amperages, plumbing layouts, and control configurations. Always verify the original pump specifications before ordering.

How can I confirm that this pump fits my tub?

Send Whirly Bros a clear photo of the original pump label, plumbing connections, and the surrounding installation area. We can help compare the important specifications before you place your order.

Why Buy from Whirly Bros?

  • Free U.S. shipping on orders over $100
  • Most orders ship the same business day
  • Expert help identifying discontinued whirlpool bath parts
  • Phone and text support before ordering
  • Specialized experience with ITT Marlow, Gemini Plus, Hydro Air, Balboa, Kohler, American Standard, and other bath-system components

Need help confirming compatibility? Call or text Whirly Bros at (951) 897-1878 before ordering. Photos of the original pump label and plumbing connections are strongly recommended.

Compatibility information is provided as a general reference. Always verify voltage, amperage, plumbing size, port orientation, control method, and available space before installation.

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  • 5 stars: 16 (94%)
  • 4 stars: 1 (6%)
  • 3 stars: 0 (0%)
  • 2 stars: 0 (0%)
  • 1 star: 0 (0%)
Some of the reviews shown are from related products the merchant grouped with this one.
A
Austin McKinney
Perfect

Perfect replacement! Thanks a lot!

Thank you, Austin! Glad you're satisfied with the replacement.

A
Anonymous
Great service on the phone

Great service on the phone, product was perfect.

k
kathy liston
We were very happy with the service and the fast shipping of this item

We were very happy with the service and the fast shipping of this item. It worked perfectly in our Jacuzzi tub in a rental unit. Highly recommend this company!

Hi Kathy, thank you for your positive feedback! We're glad the pump worked perfectly and that you were satisfied with our service and shipping. We appreciate your recommendation!

L
Laura Tibbo
Setup worked perfectly for older style tub

Setup worked perfectly for older style tub. Jessie was very helpful!

Hi Laura, thank you for your wonderful review! We're glad Jessie could assist you and that the setup went smoothly. Enjoy your tub!

N
Norman Sager
Direct fit

No problems pump was identical to old one.. All fittings and mounting lined uptlyly perfectly

Thanks for the kind review ๐Ÿ˜Š

A
Anonymous
Perfect replacement fit for my tub and works

Perfect replacement fit for my tub and works better than original when it was new

A
Anonymous
Not as much power as the exact pump that was 34 years old

Not as much power as the exact pump that was 34 years old. They changed the mounting holes so that made it more difficult to mount under a massive tub that was installed before the bathroom was even framed in.

thx for taking time to review, our pump delivers enough flow for most, if you want a pump with more power you can always upgrade to one with more amperage but do note that the bottom pump feed line would need to be extended by 1 inch. This is just the easiest option available.

I am always open to providing more information if its helpful to customers. but mots just want an easy to install replacement.

m
mike halsema
Quick shipping and accurate

Quick shipping and accurate parts

Hi Mike, thank you for your kind words! We're glad the shipping was quick and the parts were accurate. We appreciate your support!

K
Kenneth waddle
Perfect

Perfect

Hi Kenneth, thank you for your perfect rating! We're glad you're satisfied with the pump.

J
John Triay
Great price and installation was a breeze

Great price and installation was a breeze.

Thanks for great review John- We appreciate your business

-Jesse Paredes

j
jerry hunt
good product and shipping

fast shipping, packed very well, had to redrill mountholes which was a pain but pump seems to work well. i thought base mount was kinda cheap made plastic but we will see how it holds up. ii havenโ€™t used it but a few times but so far so good . no one told me if it had warranty no complaints here so far๐Ÿ‘

Thanks for the great review. You do have 1 yr warranty from the date it was received. We appreciate your business

Jesse Paredes

A
Anonymous
Perfect replacement motor

Perfect replacement motor, installed with no hassles, works like a charm

M
Michael Westin
Itโ€™s fantastic !

I just installed this pump for a direct replacement of the ITT pump originally from Ameribath. It fit perfectly and installed in about 20 minutes. No plumbing or electrical changes necessary. The variable speed upgrade is a real bonus. Highly recommend!

L
Leland Powell

Perfect fit

Hi Leland, we're glad to hear the pump fits perfectly! Thanks for your review.

T
Tony Alderisio

Pump was exact fit replacement. Works great.

Hi Tony, glad to hear the pump fits perfectly and works great. Thanks for sharing your feedback!

R
Rajendra Patel
Ap

Easy to place order and delivered on time.

Hi Rajendra, thank you for your positive feedback! We're glad you had a smooth experience. Enjoy your new pump!

J
Jonathan Taylor
Great whirlpool control system and shipping

This company ships fast and they do a good job packing, their prices are super fair, best deal online for sure.

Hi Jesse, thank you for your kind words! We're glad you're satisfied with the product and our service. Enjoy your whirlpool control system!