--- title: "Freeze Guard Not Working: Sensor, Setting, or Pump Problem?" description: "If your pool freeze guard did not start the pump on a cold night, check the air sensor, the setting, the baskets, and the power before you call a pro." url: https://marinapool.multisites.ai/post/freeze-guard-not-working-pool publisher: Marina Pool Services phone: +1-817-896-1120 quote: https://marinapool.multisites.ai/contact --- # Freeze Guard Not Working: Sensor, Setting, or Pump Problem? When freeze guard does not start the pump, the cause is usually one of four things: the freeze setting is off, the air sensor is failed or misreading, the pump has no flow or no power, or the controller depends on a weather feed that is down. Check the screen, then call a pro. Freeze and weatherPublished October 21, 20264 min read ## Why would freeze guard fail to start my pump? Freeze protection is a controller job. The controller reads an air sensor, and when the air is below the set point, it turns the pump on. ProTuff Products says it “fails quietly when it is not” set up right. Most failures trace back to the setting, the sensor, the flow, or the power. Use the table below to match what you saw to a likely cause. These come from the Hayward, Pentair, and Jandy manuals as summarized by ProTuff, plus the Pentair and Hayward freeze pages. What you saw Likely cause Who fixes it Pump off, no freeze message Freeze protection off for that circuit You can check the setting; a pro confirms “AIR SENSOR OPEN” (Jandy) or “Air Err” (Pentair EasyTouch) Air sensor disconnected or failed Pool pro Pump starts late Sensor in direct sun reads warm Move or have a pro move the sensor Pump ran, then stopped Flow switch saw no flow, or basket blocked Clear the baskets; pro if it repeats Pump never ran, no power Breaker or outage Pro for breaker faults Wi-Fi controller silent Internet or weather service down Pro; add a backup plan Pump ran on the pool but not the cleaner or booster Those circuits not freeze protected Pro or controller menu ## Is the setting turned on? Check this first. Settings can be on for the filter pump and off elsewhere. ProTuff’s step list says to turn freeze protection on “for each piece of equipment” that needs moving water, such as the filter pump, spa, cleaner or booster pump line, or a water feature. On Pentair, the pump manual says protection is provided by choosing YES at the “ON WITH FREEZE” item in the circuit function menu. If that is set to No, “nothing is watching.” Also look at the start temperature. Hayward and Jandy default to 38 degrees F, while Pentair EasyTouch uses about 35 or 36. A start temperature set too low gives you less margin. Our post on pump temperature in a freeze has the full table. ## Is the air sensor working? Freeze mode runs from air temperature, not water temperature. The sensor must work and sit in the shade. A sensor in direct sun reads warm and delays freeze mode. Warnings from the manuals include: - Hayward AquaRite S3: if the air sensor is disabled after freeze protection is on, protection will no longer activate. - Jandy: when “AIR SENSOR OPEN” shows, freeze protection will not operate correctly. - Pentair EasyTouch: an air sensor that is not connected shows “Air Err.” Treat any of these as urgent in cold weather. A [freeze sensor](https://marinapool.multisites.ai/glossary/freeze-sensor) is small, but it decides whether the whole system works. Replacing or rewiring one is a job for a qualified pool professional, not a home repair. ## Is the pump actually moving water? A running pump with a blocked path does little. A skimmer or [pump basket](https://marinapool.multisites.ai/glossary/pump-basket) packed with fall leaves cuts flow. On Hayward OmniLogic and Pro Logic controllers with a flow switch and flow monitoring on, the pump shuts down if it detects no flow. Empty baskets before a cold front. Also check whether the pump has lost prime, which stops water from moving. On a variable-speed pump, the freeze speed matters too. It needs to move water through every exposed pipe. A pool with long pipe runs or raised equipment needs more flow than a compact pad. Start from the pump manual and confirm you see water at the returns. ## What should I write down before I call? A few notes make the visit faster. Record the temperature the air reached, what the controller screen said, and whether the pump ran at all. Note any error text, such as an air sensor message, and take a photo of the screen. Say whether the power flickered. Say whether the spa was in use. Note whether baskets were full of leaves. These details point to the setting, the sensor, the flow, or the power. ## Could something else be overriding it? Yes. Three common cases: 1. **Spa use.** Jandy’s manual says using the spa during freezing conditions overrides freeze protection for non-spa equipment, such as a cleaner or booster pump. 2. **A manual override.** Hayward Omni systems let you override freeze protection for 60 minutes. Touch the button again to resume it. 3. **A Wi-Fi weather feed.** Pentair IntelliConnect has no local air sensor in the loop. It uses an internet weather service, and the Pentair warning says it will not work if the connection or the weather site is down. ## What if the power failed? Then the pump cannot run, whatever the settings say. Hayward says to turn off all pool equipment breakers, and Pentair says the same, so you can assess the equipment before it all restarts. If ice has formed, Hayward says to wait for it to melt before restoring power. Cracks in frozen pipes will not leak until they thaw, according to Pentair. If you find damage, see [freeze damage repair](https://marinapool.multisites.ai/freeze-damage-repair). ## Should I call a pro? Yes, if the pump did not start, a sensor shows an error, or you are not sure how your controller is set. Marina Pool Services checks existing freeze guard settings, connected equipment, and circulation, including the pump and related parts that could stop the system from working during freezing conditions. See the [pre-freeze checklist](https://marinapool.multisites.ai/post/pool-freeze-checklist-before-first-cold-front) for what to test each fall. Your [freeze guard](https://marinapool.multisites.ai/glossary/freeze-guard) is worth testing before the next cold front. ## Next step Read about [Marina’s Freeze Guard service](https://marinapool.multisites.ai/our-services/freeze-guard), then call (817) 896-1120 or send a request through the [quote form](https://marinapool.multisites.ai/contact). Free estimates are available for qualifying services. ## Frequently asked questions ### Why did my pool pump not turn on in the freeze? Common reasons: freeze protection is off for that circuit, the air sensor is open or disconnected, the pump basket is blocked so a flow switch shuts the pump down, or the power is out. Check your controller screen for an error or a freeze indicator, then ask a pro to inspect the system. ### Can I raise the freeze temperature to be safe? On Hayward and Jandy controllers, yes, within the range your manual gives, about 33 or 34 to 42 degrees F. A higher setting starts the pump earlier and runs it longer. Pentair EasyTouch and IntelliTouch manuals give no adjustment. ### Is the pump's built-in cold sensor enough? No. Pentair and Hayward say the pump's own thermal feature is not for freeze protection of the pool, and it steps aside once the pump is connected to automation. The controller's air sensor and settings are what count. ### Who should fix a failed freeze sensor? A qualified pool professional. Sensors and controllers involve low-voltage and line-voltage wiring. Do not open the equipment panel yourself. Marina Pool Services can inspect the setup and circulation, and recommend a repair. ## Pool terms on this page - [Variable-speed pump](https://marinapool.multisites.ai/glossary/variable-speed-pump) - [Freeze protection](https://marinapool.multisites.ai/glossary/freeze-protection) - [Freeze sensor](https://marinapool.multisites.ai/glossary/freeze-sensor) - [Water feature](https://marinapool.multisites.ai/glossary/water-feature) - [Booster pump](https://marinapool.multisites.ai/glossary/booster-pump) - [Freeze guard](https://marinapool.multisites.ai/glossary/freeze-guard) - [Flow switch](https://marinapool.multisites.ai/glossary/flow-switch) - [Pump basket](https://marinapool.multisites.ai/glossary/pump-basket) - [Skimmer](https://marinapool.multisites.ai/glossary/skimmer) - [Spa](https://marinapool.multisites.ai/glossary/spa) ## Sources 1. [ProTuff Products: Pool Freeze Protection Settings by Controller Brand](https://www.protuffproducts.com/how-to/pool-freeze-protection-settings/) 2. [Pentair: Pool Freeze Protection (Eight Tips)](https://www.pentair.com/en-us/education-support/water-education-center/pool-and-spa-education/pool-freeze-protection.html) 3. [Hayward: Pool Freeze Protection Tips for Freezing Weather](https://www.hayward.com/blog/post/pool-freeze-protection-tips-for-freezing-weather) 4. [Pentair: Winter Weather Pool Protection](https://www.pentair.com/en-us/education-support/water-education-center/winter-storm-pool-protection.html) Written by Marina Pool Services and checked against the sources above on October 21, 2026. City rules and product guidance change, so check the linked page before you act. Follow product labels for any pool chemical. ## Keep reading - [Your Pool Freeze Checklist Before the First Cold FrontBefore a cold front, confirm freeze protection is on, the air sensor reads correctly and sits in shade, the baskets are clear, and the pump moves water at the returns. Know what to do if power fails. Pentair and Hayward both say to keep equipment running until temperatures return to normal.](https://marinapool.multisites.ai/post/pool-freeze-checklist-before-first-cold-front) - [Freeze Protection and Winter Pool Care in TexasPool freeze protection in Texas means keeping water moving and equipment protected when air temperatures fall to freezing. A freeze guard senses the cold and starts your pump or equipment on its own. Before a hard freeze, check the freeze setting, the power supply and exposed pipes. Read your equipment manual, because settings differ by brand.](https://marinapool.multisites.ai/guides/freeze-protection) - [What Temperature Should You Run the Pool Pump in a Freeze?Most controllers start the pump on their own near 38 degrees F: Hayward and Jandy default to 38, and Pentair EasyTouch uses about 35 to 36. If you have no automation, Pentair and Hayward say to run the pump around the clock until temperatures return to normal.](https://marinapool.multisites.ai/post/pool-pump-temperature-in-a-freeze) - [The North Texas Pool Calendar, Month by MonthNorth Texas pools need work all year. DFW's average last freeze is March 12 and first freeze is November 22. Highs reach about 96 degrees in July and August. Start up in spring, test often in summer, clear leaves in fall, and set freeze protection before late November.](https://marinapool.multisites.ai/guides/north-texas-pool-calendar) - [Do You Need to Close Your Pool in North Texas?Most North Texas pool owners keep the pool open and run freeze protection during cold snaps. Texas freezes are short, so full closing is usually not needed. Consider winterizing if a long hard freeze is forecast, if power may fail, or if your equipment cannot circulate water on its own.](https://marinapool.multisites.ai/post/close-your-pool-in-north-texas) - [What the February 2021 Freeze Means for Grapevine PoolsIn February 2021, DFW Airport hit -2 F on February 16 and stayed at or below freezing for 139 hours in one stretch, per the National Weather Service. Grapevine pool owners can prepare by checking freeze protection on equipment, keeping water moving, and knowing who to call before the next hard freeze.](https://marinapool.multisites.ai/post/grapevine-pool-freeze-2021-lessons) ## Need a hand with your pool? Call or text and tell us what your pool needs. Estimates are free for qualifying services, and same-day estimates are possible when the schedule allows. [Call (817) 896-1120](tel:+1-817-896-1120)[Get a quote](https://marinapool.multisites.ai/contact) ![A pool technician working on an equipment pad](https://marinapool.multisites.ai/_astro/technician-equipment-pad.BW5xZMNY_Zum1K5.webp)