Chemistry probes are not designed to withstand freezing conditions. Probes must be removed and stored according to winterization procedures. Freeze damage will result in permanent probe failure and is not covered under warranty.
Overview
Freeze Protection is a built-in safety feature on every Attendant, designed to safeguard your pool and spa equipment whenever outdoor temperatures drop near or below freezing.
When activated, The Attendant automatically runs your circulation pumps—and, if configured, your heater—to keep water moving through the plumbing. Because moving water is far less likely to freeze, this continuous circulation helps prevent cracked pipes, ice buildup, and costly equipment damage.
By keeping the system in motion, Freeze Protection helps protect both your equipment and your investment during cold weather conditions.
How It Works
Freeze Protection is typically enabled by default when The Attendant is installed. By default, the system will engage when the outdoor air temperature falls below 40°F (4.4°C) and will run the circulation pumps at 100% speed.
These factory settings are optimized to provide reliable protection for most pools and spas without requiring any user adjustments.
When Freeze Protection activates, The Attendant automatically cycles through all configured flow paths—pool, spa, and water features. Every 20 minutes (adjustable), the system switches to the next available path to ensure that all plumbing lines, valves, and features receive water flow, preventing ice formation in any part of the system.
Operational Logic During Freeze Protection
When Freeze Protection starts, The Attendant follows a specific hierarchy to determine pump and heating behavior:
- If a control is off or on when Freeze Protection begins, the pump runs at the Freeze Protection speed.
- If a water feature’s maximum speed is lower than the Freeze Protection speed, the pump runs at the lower (max feature) speed.
- If a water feature’s minimum speed is higher than the Freeze Protection speed, the pump runs at the higher (min feature) speed.
- If Emergency Heating turns on, pumps will run at the active heating speed defined in the temperature control settings.
- Emergency Heating will continue until the Body of Water’s minimum water temperature is exceeded, then automatically turn off.
When the freeze event ends, The Attendant resumes your normal schedule automatically. Any devices that were running before Freeze Protection started will not restart unless they are part of a schedule.
Important Note for Pools with Covers
If your pool has a cover, make sure your Attendant configuration reflects it. This can be done by either:
Winterizing the pool or individual water features, or
Adding the Pool Cover as a device in your system.
Updating this setting ensures that Freeze Protection won’t activate features that spill or pump water onto the cover, helping you avoid unnecessary wear, damage, or pooling water during cold weather.
View the Pool Cover Article by clicking here.
Configuration Options
You can adjust Freeze Protection settings in Installer Mode by selecting the Site tab, then tapping anywhere in the gray Freeze Protection box.
Mode
- Enabled (Default) – Uses the onboard air temperature sensor. If the sensor fails, The Attendant automatically switches to internet-based weather data.
- Thermistor Only – Uses only the onboard sensor.
- Internet Only – Uses only online weather data.
- Disabled – Turns Freeze Protection off entirely.
Minimum Pump Speed
Defines the lowest speed allowed for pumps during Freeze Protection.
Default: 100%
Activating Temperature
Sets the ambient air temperature at which Freeze Protection activates.
Default: 40°F (4.4°C)
The mobile app will show “standing by” once the temperature is within 5°F of this threshold.
Auto Pause for Heating Controls
Temporarily pauses Freeze Protection for a set duration if a heating function (e.g., spa heat) is already running.
Default: Off
Emergency Heating (Turn On Heating Devices When Below Minimum Temperature)
Allows The Attendant to automatically activate a heater when water temperature (not air temperature) drops below the Body of Water’s configured minimum.
Default: Off
Flow Cycle Interval
Sets how long water circulates through each flow path before switching to the next.
Default: 20 minutes (adjustable)
Avoid Freeze Protection if No Internet Weather Data
Prevents activation when weather data is unavailable for extended periods (not applicable in Thermistor Only mode). Default: On
Remember Which Controls Were On Before Freeze Protect Started
When enabled, controls that were turned ON before Freeze Protection started will remain ON once the Freeze Protect event ends. Default: Off
Note: If a previously turned-on control was scheduled to be turned off during the Freeze Protect period, it will be turned OFF. If a control was originally off, and was scheduled to turn on during Freeze Protect, it will be turned ON.
Water Feature Freeze Protection
Under the Site tab, each water feature can be individually configured to participate in or be excluded from Freeze Protection.
Body of Water Freeze Protection
The Attendant also has a unique ability to winterize certain specific water features or bodies of water while keeping others active. A good example of when this is useful is a situation where the main pool gets winterized but the spa may be left running for the winter.
If you wish to use this capability, toggle the Winterized option on any given water feature or body of water while in Installer Mode. When you do this, the system will prevent you from activating any controls associated with those winterized bodies or features.
Checking the Status or Pausing Freeze Protection Mode
When Freeze Protection mode actively starts up, you will see a message in the mobile app letting you know. You can review the current path of water that is being protected by viewing the alert mobile app displays and also from Freeze Protection status page.
While in normal mode, if you click on the hamburger menu and go to Maintenance followed by Freeze Protection, you can see how the system will (or is) route water when it gets too cold. In configurations that have valve actuators, you can see which actuator positions will be cycled to ensure all parts of the pool get water flowing through them regularly. You can also use this page to temporarily pause Freeze Protection mode should you need to.
You can pause Freeze Protection mode by pressing the blue “Pause” button and setting the amount of time to pause. Options range from 15 minutes to 4 hours. Once this time elapses, Freeze Protection mode will be re-enabled.
Reviewing the History of Freeze Protection
You can view when Freeze Protection is active by looking at the Alerts & History section of the mobile app. There you will see a history of events that have taken place.
Freeze Protection vs. Winterizing Your Pool
Winterizing (Closing Your Pool)
Winterizing—often called closing your pool—means shutting down all or parts of the pool for the season. A pool professional will usually:
- Balance the water
- Drain water from plumbing lines and equipment (like pumps and heaters)
- Add antifreeze or other protection as needed
This is most common in colder northern climates where pools are out of use for months at a time.
Freeze Protection (Keeping Things Open)
Freeze Protection is different. Instead of shutting the pool down, the Attendant keeps water moving whenever temperatures drop near freezing. Because moving water is much less likely to freeze, this helps protect pipes, pumps, heaters, and water features from damage.
Freeze Protection is popular in moderate climates—places where winters are milder, but there are still occasional freezing nights. It can help you:
- Avoid a full pool closing
- Keep water features open longer
- Extend your swimming season
Using Both Together
You don’t have to choose one or the other—you can do both. For example, you might winterize certain water features (like fountains or spillovers) while leaving the main pool running on Freeze Protection.
If you’d like to do this, simply toggle the Winterized option for any body of water or feature in Installer Mode. The Attendant will then keep those items shut down while still protecting the rest of your system.
What to do if you have an Autofill installed
If your pool or spa has an Autofill device configured, keep in mind that it will still operate even if you’ve winterized part of your system.
If you don’t want the Autofill to add water to a winterized pool or spa, you’ll need to turn it off in the Mobile App.
How to Disable Autofill:
- Open the Mobile App and go to the main screen.
- Tap the menu icon (☰) in the top corner.
- Select Maintenance → Body of Water Settings.
- Tap Autofill.
- Uncheck the Enabled box for each body of water you have winterized.
- Don’t forget to Save your changes!
This ensures that your winterized pool or spa stays protected without extra water being added.