Scheduling and Advanced Chiller SettingsUpdated 2 hours ago

Once your chiller is paired with the Tuya Smart app, a few settings make a big difference to how ready your plunge is, how clean the water stays and how much power it uses. The right approach depends on your model, so find your chiller below. Not paired yet? Start with Connect Your Tuya App.

*From around 25°C (77°F) to plunge temperature, at the recommended fill. Larger volumes, warm weather and an open lid all add time.

Before you set any schedule

• Each schedule sets a temperature, not just an on or off time. If your chiller keeps “changing back” to a temperature you didn’t choose, an old schedule is usually the reason. Open Timer in the app and delete any you don’t use.
• Schedules only run while the chiller is plugged in, switched on at the wall and connected to Wi-Fi.
• Don’t switch off at the wall between sessions. Switching off completely stops the water circulating. Still water can turn murky within 3–5 days, and the chiller has to start from scratch each time.
• Setting a schedule in Tuya Smart: Open your chiller, tap Timer, then add each schedule with its time and target temperature. Check that each one is switched on.

Part 1: Ultra X2
These chillers cool only.

• Cooling: the compressor runs until the water reaches your set temperature.
• Standby: once it’s at temperature, the compressor rests. The pump keeps circulating water through the filters, which keeps the water fresher.
• Restart: when the water warms past the temperature band (P1), the compressor starts again.

Working example: a morning plunge

Plunge in the evening instead? Shift both times so cooling starts 8–12 hours before your session.

The temperature band (P1)
P1 sets how far the water can warm before the compressor restarts. The default is 2°C, and we recommend leaving it there.

• A smaller band (for example, 0.1°C) keeps the water closer to your set point, but the compressor starts and stops far more often. That uses more power and adds wear.
• A 2°C swing isn’t noticeable in a session.

Other Ultra X2 settings
P2 is the compressor start-up delay (default 3 minutes, leave unchanged) and P3 switches the display between °C and °F. Asked for a password when changing settings? You’ve opened the technician menu. Press power to exit. You don’t need it for anything in this guide.

Part 2: Ultra X4, Ultra Max and Ultra Ice
These chillers cool and heat, so they work differently from the Ultra X2:

• There’s no P1 setting to adjust. The temperature band is set in the system, so you only need to choose your target temperatures.
• Don’t use a high “rest” temperature. On the Ultra X2, setting a temperature above the outside air lets it idle. On a chiller that heats, that would make it start heating the water. Instead, rest it at a neutral temperature close to room temperature, around 21°C (70°F), so it isn’t constantly working.
• Neutral also protects the unit. Moving through neutral means the chiller never has to work from very cold straight to hot, or back again.
• To use heat, the chiller must be in dual-temperature mode. Hold the Up button until the display shows Double, then set your temperature. See Chiller Isn’t Heating.

When to start your cold schedule
From room temperature, start it at least 6 hours before your plunge on the Ultra X4, and at least 3 hours before on the Ultra Max or Ultra Ice. Allow longer in summer, and allow time for heating too, as it’s slower in cold weather. The times and temperatures below are worked examples only. Set the temperatures that suit you.

Cold only: two schedules
Example: an 8:00 am cold plunge at 3°C (37°F). The cold schedule below suits the Ultra Max and Ultra Ice. On the Ultra X4, move it to 2:00 am.

Hot and cold: four schedules
Example: an 8:00 am cold plunge at 3°C (37°F) and a 6:00 pm hot dip at 39°C (102°F). On the Ultra X4, move the cold schedule to 2:00 am.

Using heat regularly? Change the water more often, as warm water grows bacteria much faster than cold.

Standby mode
Going away, or taking a break from plunging? Put the chiller in standby instead of switching it off at the wall. In standby, it won’t cool or heat, but the water pump and ozone generator keep running, so the water stays fresh.

1. Long-press the up arrow (right side) until a pop-up shows Normal or Standby.
2. Use the up and down arrows to select Standby.
3. Press the S button (upper right) to confirm.
4. Press the power button once more. The chiller now runs in standby.

To start cooling or heating again, follow the same steps and select Normal.

Ozone settings (Pro models and Ultra Ice)

• The ozone cycle runs for 5 minutes by default. You can adjust it in the Tuya app.
• Schedule ozone for times nobody is using the plunge, such as overnight.
• After a cycle, take the lid off and let the surface air out for 5–10 minutes before you get in.

More detail in Ozone: How It Works and How to Use It Safely.

Through the seasons

• Winter: keep the water moving, or drain the system if it will sit below 1°C (34°F).
• Summer: allow longer to reach your target, and keep the lid on.

See Using Your Equipment in Cold and Hot Climates.

Every session, whatever your model
Switch the chiller off at the panel or in the app before you get in the water, and back on once you’re out. Never plunge while it’s running. Keep the filters on their schedule and the water above the chiller.

Need a hand setting this up? Contact us with your model, when you like to plunge and your target temperatures, and we’ll suggest a schedule.