{"title":"Harwil Flow Switches","description":"\u003cp\u003eHarwil Flow Switches are trusted flow control components used in pool, spa, water treatment, HVAC, and industrial applications. These switches help monitor water movement and protect equipment by confirming proper flow before pumps, heaters, chemical systems, or other components operate.\u003c\/p\u003e\u003cp\u003eBath \u0026amp; Spa Parts Online carries Harwil flow switches, sensors, and related replacement parts for service professionals and equipment owners. Harwil products are especially valuable in pool and spa systems where accurate flow detection supports safety, heater protection, and reliable performance. Built for demanding environments, Harwil Flow Switches help maintain efficient operation and reduce the risk of equipment damage caused by low-flow conditions.\u003c\/p\u003e","products":[{"product_id":"q12ds501-54sno1","title":"Harwil Flow Switch [1\/2\"Thd] [Q12DS Kit] [Hubble Fitting \u0026 1\/2\"Cplr] (Q12DS501.54SNO1)","description":"\u003cp\u003eA flow switch helps verify water movement in a compatible system so connected equipment can respond appropriately when flow is present, and this Harwil version is a Q12DS kit with a 1\/2 inch threaded connection, Hubble fitting, and 1\/2 inch coupler using the Q12DS501.54SNO1 reference. Kits like this are useful when a complete flow-switch setup is preferred over sourcing multiple installation pieces separately.\u003c\/p\u003e\u003cp\u003eThis package has practical value because it combines the switch with related connection hardware, helping simplify installation planning and replacement work. A properly selected Harwil flow switch kit helps support cleaner service, more dependable flow verification, and easier restoration of the original control behavior.\u003c\/p\u003e\u003cp\u003eThis type of part is especially useful when servicing systems that depend on accurate flow confirmation for safe operation and the original switch assembly needs a more complete replacement solution. That helps keep repairs organized and more dependable.\u003c\/p\u003e\u003cp\u003eInstalled in the proper application, this flow switch kit helps support reliable flow detection and cleaner overall control integration.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eQ12DS flow switch kit with 1\/2 inch threaded connection\u003c\/li\u003e\n\u003cli\u003eIncludes Hubble fitting and 1\/2 inch coupler\u003c\/li\u003e\n\u003cli\u003eHelps verify water movement in compatible systems\u003c\/li\u003e\n\u003cli\u003eUseful when replacing a complete flow-switch assembly\u003c\/li\u003e\n\u003cli\u003eImproves installation convenience and service confidence\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Harwil","offers":[{"title":"Default Title","offer_id":28244965648,"sku":"Q12DS501-54SNO1","price":72.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1751\/9347\/products\/601011.jpg?v=1486186843"},{"product_id":"q12ds501-54sno1k","title":"Harwil Q12DS Flow Switch Kit [1\/2\" MPT] [2A] (Q12DS501.54SNO1K)","description":"\u003cp\u003eA flow switch kit helps verify water movement in a compatible system while simplifying installation through a matched package of parts, and this Harwil Q12DS version is a 2 amp kit with a 1\/2 inch male pipe thread connection using the Q12DS501.54SNO1K reference. Kits like this are useful when a more complete replacement approach is preferred over piecing together separate components.\u003c\/p\u003e\u003cp\u003eThis kit has practical value because it is built around a known Harwil flow-switch platform and provides a cleaner service path when restoring original flow-sensing behavior. A properly selected kit helps support dependable water-motion confirmation and contributes to more consistent heater or equipment protection.\u003c\/p\u003e\u003cp\u003eThis type of part is especially useful during repair work where the original flow switch and related connection setup need to be renewed together to avoid repeat service issues. That helps keep the repair more complete and more dependable.\u003c\/p\u003e\u003cp\u003eInstalled in the proper application, this flow switch kit helps support reliable flow sensing and cleaner overall system service.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eHarwil Q12DS flow switch kit rated at 2 amps with 1\/2 inch male pipe thread connection\u003c\/li\u003e\n\u003cli\u003eHelps verify water movement in compatible systems\u003c\/li\u003e\n\u003cli\u003eUseful when replacing a flow switch with a more complete kit solution\u003c\/li\u003e\n\u003cli\u003eSupports dependable heater and equipment protection\u003c\/li\u003e\n\u003cli\u003eImproves installation convenience and service confidence\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Harwil","offers":[{"title":"Default Title","offer_id":44739634954395,"sku":"Q12DS501-54SNO1K","price":79.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1751\/9347\/files\/26-578-1101_XL.jpg?v=1715147676"},{"product_id":"q10n-106911-lb-no-2f","title":"Harwil Q9DS to Q10N Flow Switch Kit [1-1\/2\"x1\" Bushing] (Q10N\/106911\/LB\/NO\/2F)","description":"\u003cp\u003eA flow switch kit helps adapt or replace a compatible flow-sensing setup while preserving dependable water-motion verification, and this Harwil version is a Q9DS to Q10N style kit with a 1-1\/2 inch by 1 inch bushing using the Q10N\/106911\/LB\/NO\/2F reference. Adapter-style kits are especially useful when upgrading or converting between related flow switch formats in an existing system.\u003c\/p\u003e\u003cp\u003eThis kit has practical value because it combines the switch concept with the bushing solution needed to fit the intended plumbing arrangement. That helps simplify what could otherwise become a more pieced-together repair. A properly selected Harwil kit helps support cleaner conversion work and more dependable restored control logic.\u003c\/p\u003e\u003cp\u003eThis type of part is especially useful during service when an older switch arrangement is being updated to a compatible Q10N-based solution. That helps keep the system working properly without requiring a broader plumbing redesign.\u003c\/p\u003e\u003cp\u003eInstalled in the proper application, this flow switch kit helps support cleaner adaptation work and more dependable flow-based protection.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eHarwil flow switch kit for Q9DS to Q10N style conversion applications\u003c\/li\u003e\n\u003cli\u003eIncludes 1-1\/2 inch by 1 inch bushing support\u003c\/li\u003e\n\u003cli\u003eHelps restore or adapt compatible flow-sensing setups\u003c\/li\u003e\n\u003cli\u003eUseful during switch conversion and service work\u003c\/li\u003e\n\u003cli\u003eImproves installation efficiency and control confidence\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Harwil","offers":[{"title":"Default Title","offer_id":44739635019931,"sku":"Q10N-106911-LB-NO-2F","price":133.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1751\/9347\/files\/26-578-1010_XL.jpg?v=1715147676"},{"product_id":"q-12ds50jacuzzinotee","title":"Harwil Q12DS50 Jacuzzi Whirlpool Bath Flow Switch (Q-12DS50JACUZZINOTEE)","description":"\u003cp\u003eA flow switch helps verify water movement in a compatible whirlpool bath system so connected equipment can operate only under the correct conditions, and this Harwil Q12DS50 version is intended for Jacuzzi whirlpool bath applications using the Q-12DS50JACUZZINOTEE reference. In bath systems, reliable flow sensing plays a major role in protecting equipment and preserving intended operating logic.\u003c\/p\u003e\u003cp\u003eThis switch has practical value because it is associated with a recognizable Jacuzzi whirlpool bath application rather than serving only as a generic control component. A properly selected Harwil replacement helps support cleaner installation, more dependable flow confirmation, and better continuity with the original system design.\u003c\/p\u003e\u003cp\u003eThis type of part is especially useful when a whirlpool bath system is experiencing flow-related interruptions or unreliable switch behavior and a direct-fit style replacement is preferred. That helps keep the repair targeted and more dependable.\u003c\/p\u003e\u003cp\u003eInstalled in the proper application, this flow switch helps support dependable water-motion detection and cleaner overall system control.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eHarwil Q12DS50 flow switch for compatible Jacuzzi whirlpool bath applications\u003c\/li\u003e\n\u003cli\u003eHelps verify water movement before connected equipment operates\u003c\/li\u003e\n\u003cli\u003eUseful when replacing an unreliable or failed flow switch\u003c\/li\u003e\n\u003cli\u003eSupports dependable control logic and equipment protection\u003c\/li\u003e\n\u003cli\u003eImproves application-specific replacement confidence\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Harwil","offers":[{"title":"Default Title","offer_id":44739635544219,"sku":"Q-12DS50JACUZZINOTEE","price":79.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1751\/9347\/files\/26-578-1040_XL.jpg?v=1715147677"},{"product_id":"1710-14","title":"Harwil D1 Q10N Flow Switch [1\" MPT] [0.5A] (1710-14)","description":"\u003cp\u003eA flow switch helps confirm water movement in a compatible system before connected equipment operates, and this Harwil D1 Q10N version is a 0.5 amp model with a 1 inch male pipe thread connection using the 1710-14 reference. Light-duty flow switches like this are useful in control applications where accurate flow verification matters more than heavy switching capacity.\u003c\/p\u003e\u003cp\u003eThis switch has practical value because it is tailored for a specific flow-monitoring role and connection format, helping preserve the original design of compatible equipment. A properly selected Q10N switch helps support dependable control response and contributes to more consistent protection against no-flow operating conditions.\u003c\/p\u003e\u003cp\u003eThis type of part is especially useful when replacing an original switch that has become unreliable, stuck, or non-responsive. That helps restore the intended safety logic without forcing broader system changes.\u003c\/p\u003e\u003cp\u003eInstalled in the proper application, this flow switch helps support accurate flow detection and cleaner equipment protection.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eHarwil D1 Q10N flow switch rated at 0.5 amp with 1 inch male pipe thread connection\u003c\/li\u003e\n\u003cli\u003eHelps verify water movement in compatible systems\u003c\/li\u003e\n\u003cli\u003eUseful in lighter-duty control applications\u003c\/li\u003e\n\u003cli\u003eSupports dependable heater and equipment protection logic\u003c\/li\u003e\n\u003cli\u003eImproves service accuracy and operating confidence\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Harwil","offers":[{"title":"Default Title","offer_id":44739635871899,"sku":"1710-14","price":85.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1751\/9347\/files\/26-578-1005_XL.jpg?v=1715147681"},{"product_id":"q10-ds-dimension-1","title":"Harwil Q10DS Dimension One Flow Switch (Q10-DS\/DIMENSION 1)","description":"\u003cp\u003eA flow switch helps verify water movement in a compatible system before connected equipment is allowed to run, and this Harwil Q10DS version is intended for Dimension One applications using the Q10-DS\/DIMENSION 1 reference. Flow switches like this are important where reliable water-motion sensing supports both safety and correct system sequencing.\u003c\/p\u003e\u003cp\u003eThis switch has practical value because it is tied to a recognizable application family rather than serving only as a generic substitute. A properly selected Harwil Q10DS switch helps support cleaner replacement work and contributes to more dependable flow-based protection in the original setup.\u003c\/p\u003e\u003cp\u003eThis type of part is especially useful when a Dimension One system is showing signs of flow-switch failure, such as inconsistent operation or false no-flow conditions. That helps keep repairs focused on the actual control component causing the issue.\u003c\/p\u003e\u003cp\u003eInstalled in the proper application, this flow switch helps support dependable flow verification and cleaner overall system operation.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eHarwil Q10DS flow switch for compatible Dimension One applications\u003c\/li\u003e\n\u003cli\u003eHelps verify water movement before connected equipment operates\u003c\/li\u003e\n\u003cli\u003eUseful when replacing a failed or unreliable flow switch\u003c\/li\u003e\n\u003cli\u003eSupports dependable heater and control-system protection\u003c\/li\u003e\n\u003cli\u003eImproves replacement accuracy and service confidence\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Harwil","offers":[{"title":"Default Title","offer_id":44739635904667,"sku":"Q10-DS-DIMENSION-1","price":135.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1751\/9347\/files\/26-578-1025_XL.jpg?v=1715147680"},{"product_id":"q-12ds-c2-2-6m-no-4f","title":"Harwil Q12DS-C2 Beach Comber Molex Flow Switch (Q-12DS-C2\/2\/6M\/NO\/4F)","description":"\u003cp\u003eA flow switch helps detect water movement in a compatible system so control logic can respond appropriately, and this Harwil Q12DS-C2 version is intended for Beach Comber Molex style applications using the Q-12DS-C2\/2\/6M\/NO\/4F reference. Application-specific flow switches are useful where preserving original connector style and control behavior matters during replacement.\u003c\/p\u003e\u003cp\u003eThis switch has practical value because it is tailored to a more defined equipment context rather than functioning only as a broad substitute. A properly selected Harwil Q12DS-C2 switch helps support cleaner service work and contributes to more dependable flow-based safety and control response.\u003c\/p\u003e\u003cp\u003eThis type of part is especially useful when a Beach Comber-related system develops no-flow errors or inconsistent switch behavior and the replacement needs to stay aligned with the original setup. That helps keep repairs more accurate and easier to complete with confidence.\u003c\/p\u003e\u003cp\u003eInstalled in the proper application, this flow switch helps support better flow detection and cleaner overall equipment operation.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eHarwil Q12DS-C2 flow switch for compatible Beach Comber Molex style applications\u003c\/li\u003e\n\u003cli\u003eHelps detect water movement in the intended system\u003c\/li\u003e\n\u003cli\u003eUseful when replacing a failed or inconsistent flow switch\u003c\/li\u003e\n\u003cli\u003eSupports dependable control behavior and equipment protection\u003c\/li\u003e\n\u003cli\u003eImproves replacement accuracy and service confidence\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Harwil","offers":[{"title":"Default Title","offer_id":44739635937435,"sku":"Q-12DS-C2-2-6M-NO-4F","price":88.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1751\/9347\/files\/26-578-1015_XL.jpg?v=1715147683"},{"product_id":"q12dsc2goldlin","title":"Harwil Goldline Flow Switch [Q12Ds-C2\/Goldline-G1-068005E-2] (Q12DSC2GOLDLIN)","description":"\u003cp\u003eA flow switch helps monitor water movement in a compatible system so connected equipment can operate only under the right conditions, and this Harwil Goldline version is identified as a Q12DS-C2 style replacement using the Q12DSC2GOLDLIN reference. Brand-specific switches like this are useful when preserving original equipment behavior and connection compatibility is important.\u003c\/p\u003e\u003cp\u003eThis part has practical value because matching the original Goldline-oriented flow switch can make replacement work cleaner and help avoid uncertainty around fit or control response. A properly selected Harwil switch helps support dependable flow confirmation and contributes to more reliable overall equipment protection.\u003c\/p\u003e\u003cp\u003eThis type of part is especially useful during heater or control-system maintenance where the existing flow switch has failed and the replacement needs to remain aligned with the original equipment family. That helps keep service more direct and more dependable.\u003c\/p\u003e\u003cp\u003eInstalled in the proper application, this flow switch helps support cleaner flow sensing and more dependable system control.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eHarwil flow switch for compatible Goldline-style applications\u003c\/li\u003e\n\u003cli\u003eBased on the Q12DS-C2 replacement format\u003c\/li\u003e\n\u003cli\u003eHelps verify water movement before equipment operates\u003c\/li\u003e\n\u003cli\u003eUseful when replacing a failed brand-specific flow switch\u003c\/li\u003e\n\u003cli\u003eImproves service compatibility and operating confidence\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Harwil","offers":[{"title":"Default Title","offer_id":44739635970203,"sku":"Q12DSC2GOLDLIN","price":97.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1751\/9347\/files\/Q12DSC2GOLDLIN_XL.jpg?v=1715147683"},{"product_id":"q12ds-cal-spa","title":"Harwil Q12DS Cal Spa Flow Switch (Q12DS\/CAL SPA)","description":"\u003cp\u003eA flow switch helps confirm water movement in a compatible spa system so related equipment can operate under the correct conditions, and this Harwil Q12DS version is intended for Cal Spa applications using the Q12DS\/CAL SPA reference. Flow sensing is especially important in spa systems where heaters and controls depend on dependable circulation confirmation.\u003c\/p\u003e\u003cp\u003eThis switch has practical value because it is matched to a specific application family, helping make replacement more direct and more predictable than relying on a loosely matched substitute. A properly selected Harwil switch helps support dependable control behavior and contributes to more reliable flow-based protection.\u003c\/p\u003e\u003cp\u003eThis type of part is especially useful when a Cal Spa system has an original flow switch that is no longer responding correctly to actual water movement. That helps restore system logic and reduce service uncertainty.\u003c\/p\u003e\u003cp\u003eInstalled in the proper application, this flow switch helps support cleaner flow detection and better overall equipment protection.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eHarwil Q12DS flow switch for compatible Cal Spa applications\u003c\/li\u003e\n\u003cli\u003eHelps confirm water movement before connected equipment runs\u003c\/li\u003e\n\u003cli\u003eUseful when replacing a failed or inconsistent flow switch\u003c\/li\u003e\n\u003cli\u003eSupports dependable heater and control logic\u003c\/li\u003e\n\u003cli\u003eImproves application-specific service confidence\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Harwil","offers":[{"title":"Default Title","offer_id":44739636002971,"sku":"Q12DS-CAL-SPA","price":97.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1751\/9347\/files\/26-578-1020_XL.jpg?v=1715147685"},{"product_id":"q8ds-a-10502","title":"Harwil Q8DS Flow Switch [1\" MPT] [25A] [w\/Drag Strip] (Q8DS\/A\/10502)","description":"\u003cp\u003eA flow switch helps confirm water movement before connected equipment is allowed to operate, and this Harwil Q8DS version is a 25 amp model with a 1 inch male pipe thread connection and drag strip using the Q8DS\/A\/10502 reference. Heavier-duty flow switches like this are useful where the application calls for stronger switching capability and dependable response in the water path.\u003c\/p\u003e\u003cp\u003eThis switch has practical value because the drag strip design and higher amp rating make it a more purpose-built control component than a lighter-duty alternative. A properly selected Harwil Q8DS switch helps support dependable flow sensing and contributes to more reliable equipment protection in compatible systems.\u003c\/p\u003e\u003cp\u003eThis type of part is especially useful when servicing heaters or related systems that depend on a higher-rated flow switch to maintain intended operating safeguards. That helps restore original control performance more directly and with less guesswork.\u003c\/p\u003e\u003cp\u003eInstalled in the proper application, this flow switch helps support cleaner flow verification and more dependable overall system control.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eHarwil Q8DS flow switch rated at 25 amps with 1 inch male pipe thread connection\u003c\/li\u003e\n\u003cli\u003eIncludes drag strip for compatible flow-sensing applications\u003c\/li\u003e\n\u003cli\u003eHelps verify water movement before equipment operates\u003c\/li\u003e\n\u003cli\u003eUseful in higher-rated heater and control systems\u003c\/li\u003e\n\u003cli\u003eImproves service confidence and operational reliability\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Harwil","offers":[{"title":"Default Title","offer_id":44739636068507,"sku":"Q8DS-A-10502","price":99.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1751\/9347\/files\/26-578-1000_XL.jpg?v=1715147686"}],"url":"https:\/\/www.bathandspaparts.com\/collections\/harwil\/heaterparts.oembed","provider":"Bath and Spa Parts Online","version":"1.0","type":"link"}