Collection: Gemini & ITT Marlow Pumps

Gemini Pump Systems

What is a Gemini whirlpool pump?

Gemini pumps are used in whirlpool baths and spas to power jet systems. This collection highlights Gemini Pump Systems - Retrofit Kits and Pumps for upgrading and replacing whirlpool jet systems, and Gemini pumps were commonly installed by major tub and spa manufacturers.


Are all Gemini Plus pumps discontinued?

No, not all Gemini Plus pumps are discontinued. Some models are still available, but many are difficult to locate due to limited production.


Are ITT Marlow whirlpool pumps discontinued?

Many ITT Marlow whirlpool pumps are discontinued. However, compatible replacement pumps are available that match the original electrical and plumbing specifications.


What pump replaces a Gemini Plus II pump?

Replacement pumps designed to match discontinued Gemini Plus II and ITT Marlow models are commonly used. Compatibility depends on voltage, amperage, plumbing size, and mounting configuration.


Do all Gemini or ITT Marlow pumps have variable speed?

No, not all Gemini or ITT Marlow pumps are variable speed. Variable speed capability depends on whether the pump has an internal circuit board processor or is connected to an external control box with speed controls.


What does variable speed mean on a whirlpool pump?

Variable speed allows the pump’s motor speed to be adjusted, controlling water flow and jet pressure. This provides quieter operation at low speeds and stronger massage at higher speeds.


Can a single-speed pump replace a variable speed pump?

In most cases, a single-speed pump should not replace a variable speed pump unless the control system is also modified. Always match the pump type to the existing control system.


What voltage does the Gemini replacement pump use?

Most Gemini replacement pumps operate on 120 volts, but voltage and amperage should always be confirmed before ordering.


What if I’m unsure which Gemini pump I need?

If you’re unsure which pump you need, providing photos, measurements, and details of the existing pump or control box helps identify the correct replacement.

What determines variable speed on a whirlpool pump?

Variable speed is determined by:

  • A circuit board processor inside the pump housing, or
  • A separate control box that provides speed control

Not all Gemini or ITT Marlow pumps include these features.


Single Speed Pumps

  • Run at one constant speed
  • Typically controlled by an air switch
  • Simpler design and wiring

Variable Speed Pumps

  • Adjustable water flow and jet pressure
  • Controlled by internal electronics or external control box
  • Better for quiet soaking or strong massage

🔧 Replacement Compatibility Summary

Can modern pumps replace Gemini Plus or ITT Marlow pumps?

Yes. Modern replacement pumps are designed to match:

  • Voltage and amperage
  • Plumbing connections
  • Mounting style

Speed capability must match the existing control system.