How-To Guides | Spa Control System Replacement

partially burned spa computer in aged hot tub cabinet

Are you struggling to replace your hot tub’s expensive and hard to find circuit board or topside controller? Instead of hauling your old spa off to the dump, consider installing an entirely new control system!

Installation is simple for someone with average mechanical skills. You could save thousands of dollars over buying new parts for aging equipment.

Let’s take a closer look at identifying and selecting a new spa control kit for your hot tub.

yellow caution symbol CAUTION! DISCONNECT POWER FIRST!
Electrical wiring and repairs can be dangerous, especially around water, and must be performed by a qualified electrician or spa technician. Shut off electrical power to the hot tub or pool at the service panel prior to any inspections or work. DISCLAIMER


What is a Control System?

The control system, or spa pack, is the brain of the hot tub. This nerve center controls the functions and equipment in the spa, like the jet pumps, filtration time, and heater.

There are two types of control systems used in hot tubs: electronic, digital type systems and older-style mechanical air controls.

Digital Systems

New digital hot tub control system with topside control

Digital controls are solid state computer-controlled systems. The circuit board inside can run sophisticated filtration cycles and onboard diagnostics.

The control keypad on top of the spa allows communication with the control pack. When any issues arise, Error Codes will display.

Air Systems

New pneumatic hot tub control system with air buttons

Non-digital air systems have buttons that send a puff of air to switches, turning each function on or off. These pneumatic switch type controls were used on the early tubs of the 1970’s through 1990’s. While they’re still available, most air systems have been replaced by digital controls.

If your tub has an old air system, you can definitely update your spa with digital controls.

How Do I Know if I Have a Digital or Air System?

fully programmable digital topside next to simple air control topside

An easy way to tell the difference between digital and air systems is to look at the keypad connection.

Digital systems will have one electrical cord extending from the keypad to the main control pack.

An air system will have 1/8” vinyl tubes connecting each button to the control system, in addition to any electrical cords. These tubes are similar to those used in fish tanks or medical drip systems.

How Do I Choose the Right Control System?

When replacing the entire brain of a hot tub, ensure the heater, topside and physical dimensions of the system fit.

Heater Types

The style of heater that your spa already has plays a critical role when choosing a replacement control system. There are two basic heater types: High Flow and Low Flow.

two inch high flow stainless steel heater next to one inch low flow heater

  • High Flow heaters have 1.5” to 2” plumbing and are fed by a pump with a flowrate of 25 gallons per minute minimum. The pump must be at least 1.5”, and be either a dedicated, single-speed circulation or a dual-speed jet pump.
  • Low Flow heaters have ¾” to 1” plumbing with a dedicated 24-hour circulation pump that flows 10-20 gallons per minute. These pumps have a plumbing size of ¾” to 1”.

The new control system you choose will include a new heater. The plumbing and existing pumps must match up to the new pack to avoid damage to your new system.


Great! You‘ve decided on digital or air controls and selected the correct heater type. The next step is to determine the number of pumps and other circuits your tub needs.

Determine what components your tub has by following each cord attached to the control system to its respective component. Once you’ve located each component, note the voltage, which will be listed on its data label.

Once you know how many pumps/blowers your tub has and what kind of heater, you can select a control system.

We’ll use your voltage selections to pre-configure the system for an easy installation.

Setup and Installation

All control system installations are a little different, but here’s a general overview of the steps involved.

Caution: Make certain the power is disconnected before proceeding. On 240V spas, shut-off the breaker at the main panel servicing the house, and the GFCI Sub-Panel servicing the spa. On 120V spas, unplug spa from the receptacle.

  • Open spa equipment access panel.
  • Disconnect incoming power cord from equipment system.

hands removing wires from circuit board

  • Drain the hot tub.
  • Disconnect the electric and component cords from control system (pump, blower, etc.).

incoming power cord on left side of computer board, component cords on right

  • Disconnect and remove the topside controller

Note: Most topsides are attached using silicone sealant or double stick tape. Oftentimes, using fishing line or dental floss to get in between the shell of the tub and the topside helps.

  • Disconnect the plumbing from the heater.
  • Remove the control system.
  • Take an assessment of the pumps and other components. You’ll want to determine whether they can be reused or should be replaced.

Read how to replace your spa pump

  • If replacing, install the new pump(s). Note: EasyPak systems are designed to be connected to the discharge end of the pump. If plumbing cannot be manipulated to achieve this configuration, a flow switch kit will be required.

the intake is in line with motor shaft and the discharge points straight up

  • If the tub has an air blower, connect it to the plumbing. Note: Always install a new blower check valve.
Read how to replace your air blower
  • Install the new topside controller using the supplied adapter plate if necessary.

keypad separate from larger optional adapter plate

  • Install the control system and heater.

new digital control system in older spa cabinet

  • Connect the topside controller and component power cords to the control system.
  • Make necessary PVC cement connections and reconnect all plumbed components.
  • Refill the spa through the filter opening. Note: If your source water is from a well, or has other impurities, use a PreFresh hose end spa pre-filter.

always fill your tub with a hose end filter

  • Bleed any air from the plumbing by loosening the intake pump union slightly until water begins to leak out. Allow water to leak for 5 - 10 seconds, then retighten the union. This will prime the pump and prevent air locks or heater dry-fire.
  • Double check all electrical and plumbing connections.
  • Power up the control system.
  • Run the tub and inspect for leaks.
  • Set heat to desired temperature.


Wiring: Electrical hookup must be performed by a qualified electrician in accordance with local codes. All EasyPak 240 Volt control systems must be connected to an approved GFCI protected 4 wire electrical service.

120 Volt systems must be served by a grounded, GFCI protected circuit. Alternatively, they can have an optional inline GFCI cord installed, also properly grounded.

Whether the control system uses terminal blocks or wire nuts for electrical connections, ensure all connections are tight. Always follow the manufacturers torque specifications.

Electrical: Control systems are designed to operate on 120VAC or 240VAC. The primary reason for 240 Volt controls systems is to provide faster heating.

In the case of the EasyPak, 240 Volt service will operate the heater at that voltage. The pumps and other components can be configured to operate at either 120 Volt or 240 Volt.

If 120 Volt service is selected, the heater and all other circuits must be configured for 120 Volt. It’s worth noting, 120 Volt systems will not run the jets and the heater at the same time.

Plumbing: EasyPak control systems are designed to be connected to the discharge end of the pump. If plumbing cannot be manipulated to achieve this, a flow switch kit will be required.

Other controls, like Balboa systems with M7 technology, can be plumbed to either the intake or discharge of the pump.

The Spa Depot assumes no liability for the use nor makes any warranty as to the accuracy, electrical code or building code compliance, suitability or usefulness of the information provided herein. This information is not intended to replace or substitute for information contained in equipment owner’s manuals. YOU EXPRESSLY AGREE TO HOLD THE SPA DEPOT AND ITS EMPLOYEES HARMLESS FOR ANY PROPERTY DAMAGE, PERSONAL INJURY AND/OR DEATH, OR ANY OTHER LOSS OR DAMAGE THAT MAY RESULT FROM YOUR USE OF THE INFORMATION PROVIDED. No advice or information, whether oral or written, obtained by you from this web site or our employees shall create any warranty not expressly made herein. Reader agrees to assume all risk resulting from the application of any of the information provided herein. By using this web site, including any content contained therein, the visitor agrees that the use of this web site and its information product is entirely at his/her own risk. CONSULT WITH A LICENSED ELECTRICIAN, QUALIFIED SPA TECHNICIAN, AND/OR LICENSED CONTRACTOR AS APPROPRIATE.

EasyPak Spa Controls

"The new EasyPak installed quickly and cost about $300 less than the local price. We were able to replace the old spa cover with the money we saved! The old Jacuzzi is up and running again just like it was new, actually more like better than new! Your support and delivery time was second to none."

Mark Bolling
Newport News, VA

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