{"product_id":"tecmark-adjustable-pressure-switch-universal","title":"Tecmark Hydroquip Adjustable Pressure Switch - Universal - 1\/8\" NPT - 3902 3903","description":"\u003ch3\u003eTecmark HydroQuip Adjustable Pressure Switch - Universal - 1\/8\" NPT - 3902 3903\u003c\/h3\u003e\u003cp\u003eTecmark \/ HydroQuip Spa Heater Pressure Switch (aka Spaceship style) replaces 3903-DF, 3902, 3903, 34-0178 1 Amp SPST for spa equipment and heaters. \u003cspan\u003eT\u003c\/span\u003e\u003cspan\u003ehis is a very common pressure switch used by \u003c\/span\u003e\u003cspan\u003eBalboa, Gecko, Davey, Spa-quip (SpaQuip), Spa Builders, HydroQuip, Pentair and others. Usually found near the heater assembly. They were originally branded as Tecmark, but may also be labelled HydroQuip now.\u003cbr\u003e\u003cstrong\u003e\u003cbr\u003eDetails:\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\u003cspan style=\"color: rgb(43, 0, 255);\"\u003e\u003cstrong\u003ePhysically Stocked, unlike most \"drop-shipping\" websites.\u003c\/strong\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"color: rgb(43, 0, 255);\"\u003e\u003cstrong\u003eShipped from VIC, NSW, WA, QLD\u003c\/strong\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e1-5 psi 7-35kpa adjustable SPST \u003c\/li\u003e\n\u003cli\u003eFound in a large number of spa and pool heaters\u003c\/li\u003e\n\u003cli\u003eOn\/Off device that controls heater operation\u003c\/li\u003e\n\u003cli\u003eUtilises a diaphragm to sense water pressure. This closes a switch.\u003c\/li\u003e\n\u003cli\u003e1\/8\" NPT Thread rated to 1A. Fits most spa electric heaters.\u003c\/li\u003e\n\u003cli\u003eHas two Spade connectors\u003c\/li\u003e\n\u003cli\u003e3902 and 3903 are interchangeable in spa applications. \u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eVariant and Other Information:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e3902 1A, 1-5PSI Adjustable, 1\/8\" NPT\u003c\/li\u003e\n\u003cli\u003e3903 1A, 1A, 1-5PSI Fixed by glue @ 1.5PSI, but Adjustable, 1\/8\" NPT w\/o Screws\u003c\/li\u003e\n\u003cli\u003eWWDG is rebranded 390x 3A version.\u003c\/li\u003e\n\u003cli\u003e-DF has terminal screws in addition to spade connectors.\u003c\/li\u003e\n\u003cli\u003e-BP is a 3A variant. \u003cem\u003eSome \u003c\/em\u003ewere actually still 1A though. Go figure!\u003c\/li\u003e\n\u003cli\u003e99% of spa applications do not require adjustment from factory.\u003c\/li\u003e\n\u003cli\u003eThese have been rebranded by some other companies over the years.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan style=\"text-decoration: underline;\"\u003e\u003cstrong\u003eBasic Installation Instructions:\u003c\/strong\u003e\u003c\/span\u003e\u003cbr\u003e\u003cspan style=\"color: rgb(255, 42, 0);\"\u003e(To be performed by an Electrically-Qualified Person)\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e1. Preparation:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eTurn off power at the mains before beginning installation.\u003c\/li\u003e\n\u003cli\u003eApply thread tape or sealant to the switch threads.\u003c\/li\u003e\n\u003cli\u003eHand-tighten the switch until snug—do not use tools to avoid over-tightening.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e2. Initial Testing \u0026amp; Adjustment:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eUsing a multimeter, check the switch’s status before turning the power on:\n\u003cul\u003e\n\u003cli\u003eIt should read Open-circuit (no electrical continuity) when the system is off and no pumps are running.\u003c\/li\u003e\n\u003cli\u003eIf the switch is Closed-circuit (showing continuity), adjust the screw on the switch until it reads Open-circuit.\u003c\/li\u003e\n\u003cli\u003eTurn the switch slightly further in to prevent excessive sensitivity.\u003cbr\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e3. Power-On Testing:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eTurn the power on and check the switch function:\n\u003cul\u003e\n\u003cli\u003eThe switch should be Closed-circuit when the pump is running.\u003c\/li\u003e\n\u003cli\u003eIt should return to Open-circuit when the pump turns off.\u003c\/li\u003e\n\u003cli\u003eRepeat the test to confirm proper operation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e4. Note:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eDirty or clogged filters can restrict water flow, causing the switch to open unexpectedly. Ensure filters are clean for proper function.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan style=\"text-decoration: underline;\"\u003e\u003cstrong\u003ePart Numbers \u0026amp; Descriptions This Replaces: \u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e3902 - 1Amp, 1-5psi Adjustable, 1\/8\" NPT 3903 - 1Amp, 1-5psi Adjustable, 1\/8\" NPT3903-BP 3Amp, PSI Factory Set Non-Adjustable, 1\/8\" NPT 3903-DF 1Amp, 1.5psi fixed, 1\/8\" NPT, MH26414, 3903-EECS, A2F \/ 0517, 34-0178, \u003cspan\u003e3900, 3901, 3903, 3904, 3906, 3909, PRS-1100, PRS-1101, M3218, 71076, 26775, 26776, 26778, R-113, R-130, R-132B, S-1921173328, B600025, 600025,\u003c\/span\u003e\u003c\/p\u003e","brand":"Tecmark","offers":[{"title":"Default Title","offer_id":1309093852,"sku":"TC-3903","price":63.0,"currency_code":"NZD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0372\/5253\/files\/tecmark-hydroquip-adjustable-pressure-switch-universal-1-8-npt-3902-3903-electronic-parts-138.webp?v=1757632421","url":"https:\/\/heaterandspaparts.com.au\/en-nz\/products\/tecmark-adjustable-pressure-switch-universal","provider":"Heater and Spa Parts","version":"1.0","type":"link"}