How to Fill and Start a Hot Tub for the First Time

Your hot tub has arrived, the installation site is ready, and you’re almost prepared for your first soak. Before turning on the jets, however, you need to inspect, fill, prime, and start the spa correctly.

These steps explain how to get your new hot tub up and running while reducing the risk of leaks, air locks, and equipment damage.

Always review the owner’s manual for your particular model before beginning. Equipment layouts, electrical requirements, filter assemblies, and control panels can vary.

Before You Fill Your Hot Tub

Gather the following items:

Your spa’s owner’s manual
A clean garden hose
Water-testing supplies
Manufacturer-approved water-care products
A screwdriver or other tool required to remove the service panel
A clean cloth for checking plumbing connections

Confirm that the hot tub is sitting on a level, stable foundation capable of supporting its total filled weight. The site must also provide adequate drainage and meet all applicable building and electrical requirements.

Important Electrical Precautions

A 230- or 240-volt hot tub must be hardwired by a qualified electrician in accordance with the manufacturer’s instructions and applicable codes.

If you have a factory-configured plug-and-play model, connect it only as directed in its owner’s manual.

Keep the hot tub disconnected from power—or keep its GFCI breaker switched off—while filling it. Never allow a pump or heater to operate without sufficient water circulation. Running spa equipment dry can cause serious damage.

1. Open the Equipment Area

With power to the spa turned off, remove the panel covering the equipment compartment. Depending on the model, the panel may be secured with screws or designed as an access door.

Set the panel and its hardware in a safe place.

Do not leave the equipment compartment open and unattended, especially when children or pets are nearby.

2. Inspect the Plumbing Connections

Shipping and installation can sometimes loosen plumbing connections. Inspect the visible unions around the pumps and heater before adding water.

Hand-tighten any loose unions. They should be secure, but overtightening can damage the union or its gasket. Do not use pliers or another metal tool unless your owner’s manual specifically instructs you to do so.

The number and location of the unions depend on the spa’s equipment configuration. Inspect every visible connection rather than relying on a particular count.

3. Open the Gate Valves

Locate the gate valves in the equipment compartment and confirm that they are fully open. On many MyHotTub models, an open gate valve is pulled upward and secured with a plastic retaining clip.

Never operate the spa with a required gate valve closed. A closed valve can restrict circulation and potentially damage the pump or heater.

Also confirm that the spa’s drain valve is closed and its cap is installed securely.

4. Flush the Spa Before Its First Use

A newly delivered or winterized spa may contain residual water, debris, or antifreeze from manufacturing, testing, shipping, or storage.

Follow your owner’s manual for the initial flush. This may involve:

Removing the filter and filter basket or weir assembly
Rinsing the shell with clean tap water
Directing water into the jets and filter chamber
Allowing the rinse water to drain
Continuing until the water runs clear

Close and cap the drain before beginning the final fill.

5. Install the Filter

Install the clean filter according to the instructions for your model. Some filters screw into a fitting, while others sit beneath a basket and floating weir assembly.

Make sure the filter is properly seated, but do not overtighten it. If your filter includes support bands, do not remove them.

The filter should remain installed during normal spa operation.

6. Fill the Hot Tub Through the Filter Chamber

Place a clean garden hose inside the filter chamber or designated filter intake. Filling from this location helps introduce water into the plumbing and can reduce the likelihood of a pump air lock.

Fill the spa with regular tap water to the level specified in its owner’s manual. On many MyHotTub models, the recommended level is approximately two inches above the highest standard jet, excluding elevated neck or shoulder jets.

Keep these points in mind:

Never leave the spa unattended while it is filling.
Avoid overfilling, since the water level will rise when people enter.
Do not underfill the spa, because a low water level can allow air into the filtration system.
Do not turn on the power while the water level is below the required fill line.

If you use well water or have unusual source-water conditions, ask a spa-water professional whether a pre-filter or specialized startup treatment is appropriate.

7. Check for Leaks

Once the spa is full, inspect the drain, unions, pumps, heater, and visible plumbing connections.

A small amount of leftover rinse water may be harmless, but an active drip or stream should be investigated before power is restored. If a hand-tightened union continues to leak, turn off the water supply if necessary and contact Customer Service.

Do not energize the spa if water is leaking onto electrical components.

8. Restore Power

After confirming that the spa is full and the equipment area is dry, restore power according to the instructions for your electrical configuration.

The control system may perform a diagnostic check and enter a startup or priming mode. Some control panels display PR during this process.

Allow the startup sequence to proceed as directed in your manual. Avoid pressing temperature or mode buttons unnecessarily during priming, as some control systems will exit priming mode when another setting is selected.

9. Check Every Pump and Jet

Activate each pump briefly and confirm that water flows through its corresponding jets.

Strong, steady flow generally indicates that the pump has primed correctly. A humming pump with little or no water movement may have trapped air.

Do not allow an unprimed pump to continue running. Turn it off and follow the air-lock instructions below.

How to Remove a Small Pump Air Lock

If your control system is in priming mode and the procedure matches your owner’s manual:

Press the button for the affected pump or jet zone.
If it is a two-speed pump, run it on low for approximately 10 seconds.
Press the button again and run it on high for approximately 10 seconds.
Turn the pump off for 10 to 15 seconds.
Repeat the cycle until water flows steadily through the jets.

For a single-speed pump, skip the low-speed portion and use short on-and-off cycles.

Do not repeatedly operate the pump for extended periods without water flow. Stop and contact Customer Service if the pump does not prime after several short attempts.

What If the Air Lock Does Not Clear?

A larger air pocket may need to be released from a pump union. This procedure involves opening the equipment area and loosening a plumbing connection near electrical equipment, so it should be performed only when:

The exact procedure appears in your model’s owner’s manual
Power is completely off at the breaker
You can positively identify the correct pressure union
You are comfortable performing the procedure safely

When instructed by the manual or Customer Service, the pressure union may be loosened slightly until trapped air escapes and a solid stream of water appears. The union must then be securely retightened before the panel is replaced and power is restored.

If you cannot confidently identify the correct connection, leave the power off and contact a qualified spa technician. Never loosen electrical connections or reach into a powered equipment compartment.

10. Replace the Equipment Panel

Once the plumbing has been inspected and every pump is circulating properly, reinstall and secure the exterior panel.

The equipment compartment should not be left open during normal spa operation.

11. Balance and Sanitize the Water

Fresh tap water is not automatically ready for soaking. Once the spa is circulating, test and adjust:

Total alkalinity
pH
Calcium hardness
Chlorine, bromine, or the sanitizer approved for your system

Follow the spa manual and every water-care product label. Add products separately and in the recommended order. Never mix spa chemicals or add more than the labeled amount.

Keep bathers out until the water reaches a comfortable temperature and its sanitizer and balance readings are within the recommended ranges.

Before Your First Soak

Complete this final checklist:

The spa is filled to the proper level.
The drain and plumbing unions are not leaking.
Every required gate valve is open.
The filter is correctly installed.
Water flows steadily through every active jet zone.
The equipment panel is securely attached.
The GFCI operates correctly.
The water is balanced and sanitized.
The selected temperature is safe and comfortable.

When to Contact Customer Service

Turn off the spa and request assistance if you notice:

A persistent plumbing leak
A pump that runs without moving water
Repeated GFCI tripping
A burning smell or unusual electrical sound
An error code that remains after following the manual
Water around electrical equipment
A pump air lock that does not clear
Failure to heat or circulate properly

Preparing your spa carefully helps protect its pumps, heater, plumbing, and other components. Once the startup process is complete and the water is properly maintained, you can settle in and enjoy your new hot tub with confidence.