Kohler 73533-AA Replacement Guide: The Best Retrofit Kit for Discontinued Whirlpool Systems
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Last reviewed: July 21, 2026
Quick answer: If your original pump label shows Kohler 73533-AA or K-73533, the original pump and proprietary control system are obsolete. A dependable repair normally requires replacing the pump, control box and user controls together.
Whirly Bros offers two modern 120V retrofit options: a variable-speed system with a tub-mounted keypad or a three-speed system with a waterproof wireless remote.
Why Can’t You Replace Only the Pump?
The original 73533-AA combined several matched components:
- Whirlpool pump with an integrated heater
- Pump-mounted electronic controls
- Digital tub-mounted keypad
- Proprietary Telco-style communication cable
The original keypad, cable and electronics are no longer available as a dependable supported repair system. A standard replacement pump will not communicate with the old Kohler controls, so the complete operating system must be modernized.
Compare the Two 73533-AA Replacement Systems
| Feature | Variable-Speed Keypad Kit | Three-Speed Wireless Kit |
|---|---|---|
| Pump | 120V, 8.5A variable speed | 120V, 8.5A three speed |
| Controls | Tub-mounted electronic keypad | Waterproof floating wireless remote |
| Operating Modes | High, Medium, Low, Wave and Pulse | High, Medium, Low, On/Off and 30-minute timer |
| Deck Installation | Requires installation of the new keypad | No new electronic keypad required |
| Best Choice For | Maximum speed control and massage modes | Simpler installation or limited keypad access |
Option 1: Variable-Speed Keypad System
This system uses a CG Air control box and white 2.5-inch square keypad designed to fit a 1-inch mounting hole. It provides High, Medium, Low, Wave and Pulse operation.
View the 73533-AA Variable-Speed Keypad Kit →
Option 2: Three-Speed Wireless Remote System
This system uses a waterproof floating remote and does not require a new electronic keypad in the bathtub deck. It provides High, Medium and Low speeds, On/Off control and a 30-minute timer. Remote batteries are included.
View the 73533-AA Wireless Remote Kit →
Important Heater Information
The original Kohler 73533-AA pump assembly included a heater. Neither modern replacement system includes a heater.
If you want to maintain bathwater temperature during longer use, a compatible external whirlpool tub heater can be installed separately. Heater selection depends on the available space, plumbing layout and electrical supply.
View Whirlpool Tub Heater Replacements →
Installation and Fitment
- Both replacement systems operate on 120V and must not be connected directly to a 240V supply.
- The original pump base must be removed. Install the new pump on a secure, stable mounting surface.
- Most installations can reuse the existing plumbing, but previous repairs or altered plumbing may require minor adjustments.
- A pump union is included to assist with the final plumbing connection.
- Start union threads square and tighten by hand. The O-ring creates the seal; do not use Teflon tape or pipe compound on union threads.
- The pump must be connected to a properly protected dedicated GFCI circuit.
- Use a qualified technician whenever electrical or plumbing modifications are required.
What to Send Us Before Ordering
For compatibility assistance, send clear photos of:
- The complete original pump and motor label
- The original keypad and control components
- Suction and discharge plumbing connections
- The available space beneath the bathtub
Call or text Whirly Bros at (951) 897-1878 . We will help determine which replacement system is best for your installation.
Compatibility notice: Kohler® is a registered trademark of Kohler Co. Manufacturer names and part numbers are used solely for identification and compatibility reference. These aftermarket replacement systems are not manufactured, sponsored, authorized or endorsed by Kohler Co.