{"product_id":"auxiliary-slave-heater-pack-5-5kw-x300939","title":"MASTER SPAS Auxiliary Slave Heater Pack 5.5kW - X300939","description":"\u003ch2\u003eMASTER SPAS Auxiliary Slave Heater Pack 5.5kW - X300939\u003c\/h2\u003e\n\u003cp\u003eAuxiliary Slave Heater Pack 5.5 kW\u003c\/p\u003e\n\u003ch5\u003eWhat our Experts Think\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli data-section-id=\"10incgw\" data-start=\"27\" data-end=\"194\"\u003e\n\u003cstrong data-start=\"29\" data-end=\"63\"\u003eReliable supplemental heating:\u003c\/strong\u003e The 5.5kW output provides strong, consistent heat support for maintaining ideal spa water temperature even in colder conditions.\u003c\/li\u003e\n\u003cli data-section-id=\"k741ke\" data-start=\"195\" data-end=\"343\"\u003e\n\u003cstrong data-start=\"197\" data-end=\"228\"\u003eImproves system efficiency:\u003c\/strong\u003e Works as an auxiliary\/slave unit to reduce strain on the primary heater, helping extend overall system lifespan.\u003c\/li\u003e\n\u003cli data-section-id=\"woesei\" data-start=\"344\" data-end=\"447\"\u003e\n\u003cstrong data-start=\"346\" data-end=\"376\"\u003eFast temperature recovery:\u003c\/strong\u003e Helps hot tubs recover heat more quickly after use or water top-ups.\u003c\/li\u003e\n\u003cli data-section-id=\"korqir\" data-start=\"448\" data-end=\"584\"\u003e\n\u003cstrong data-start=\"450\" data-end=\"481\"\u003eDesigned for compatibility:\u003c\/strong\u003e Engineered specifically for Master Spas systems, ensuring proper integration and stable performance.\u003c\/li\u003e\n\u003cli data-section-id=\"a4othi\" data-start=\"585\" data-end=\"711\"\u003e\n\u003cstrong data-start=\"587\" data-end=\"617\"\u003eEnergy-smart support role:\u003c\/strong\u003e Activates as needed to assist heating demand, helping balance performance and energy usage.\u003c\/li\u003e\n\u003cli data-section-id=\"oyuqup\" data-start=\"712\" data-end=\"851\" data-is-last-node=\"\"\u003e\n\u003cstrong data-start=\"714\" data-end=\"749\"\u003eDurable spa-grade construction:\u003c\/strong\u003e Built to withstand continuous water exposure and long operating cycles in demanding spa environments.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch5\u003e\n\u003cbr\u003eQ\u0026amp;A\u003c\/h5\u003e\n\u003cp data-start=\"0\" data-end=\"252\"\u003e\u003cstrong data-start=\"0\" data-end=\"84\"\u003eQ: What is the MASTER SPAS Auxiliary Slave Heater Pack 5.5kW – X300939 used for?\u003c\/strong\u003e\u003cbr data-start=\"84\" data-end=\"87\"\u003eA: It is a 5.5kW auxiliary (slave) flow-through heater system designed to help maintain and boost water temperature in compatible Master Spas hot tubs and swim spas.\u003c\/p\u003e\n\u003cp data-start=\"254\" data-end=\"406\"\u003e\u003cstrong data-start=\"254\" data-end=\"299\"\u003eQ: Is this a direct OEM replacement part?\u003c\/strong\u003e\u003cbr data-start=\"299\" data-end=\"302\"\u003eA: Yes. The X300939 is an OEM Master Spas control\/heater pack component made for compatible spa systems.\u003c\/p\u003e\n\u003cp data-start=\"408\" data-end=\"563\"\u003e\u003cstrong data-start=\"408\" data-end=\"452\"\u003eQ: What power requirements does it need?\u003c\/strong\u003e\u003cbr data-start=\"452\" data-end=\"455\"\u003eA: It operates on 240V and typically requires a dedicated 30A GFCI electrical circuit for safe installation.\u003c\/p\u003e\n\u003cp data-start=\"565\" data-end=\"744\"\u003e\u003cstrong data-start=\"565\" data-end=\"604\"\u003eQ: What does a “slave heater” mean?\u003c\/strong\u003e\u003cbr data-start=\"604\" data-end=\"607\"\u003eA: It works alongside the primary heating system to improve heating efficiency and help maintain stable spa water temperature under load.\u003c\/p\u003e\n\u003cp data-start=\"746\" data-end=\"934\"\u003e\u003cstrong data-start=\"746\" data-end=\"795\"\u003eQ: Is it suitable for all Master Spas models?\u003c\/strong\u003e\u003cbr data-start=\"795\" data-end=\"798\"\u003eA: No. It is model-specific and must match your spa’s electrical and plumbing configuration—always verify compatibility before purchase.\u003c\/p\u003e\n\u003cp data-start=\"936\" data-end=\"1116\"\u003e\u003cstrong data-start=\"936\" data-end=\"981\"\u003eQ: Does it include installation hardware?\u003c\/strong\u003e\u003cbr data-start=\"981\" data-end=\"984\"\u003eA: It is typically supplied as a heater\/control pack assembly, but installation fittings and wiring may vary depending on spa model.\u003c\/p\u003e\n\u003cp data-start=\"1118\" data-end=\"1300\" data-is-last-node=\"\" data-is-only-node=\"\"\u003e\u003cstrong data-start=\"1118\" data-end=\"1167\"\u003eQ: What are the benefits of this heater pack?\u003c\/strong\u003e\u003cbr data-start=\"1167\" data-end=\"1170\"\u003eA: It helps maintain faster heat recovery, stable water temperature, and reliable spa performance during use in colder conditions.\u003c\/p\u003e\n\u003ch5\u003e\n\u003cbr\u003eMaintenance Tips\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli data-section-id=\"14s3qkz\" data-start=\"0\" data-end=\"167\"\u003eKeep the heater pack area dry, ventilated, and free of chemical vapors to protect internal relays and sensors from corrosion. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"ayuu2s\" data-start=\"168\" data-end=\"349\"\u003eEnsure proper water flow at all times—clean filters regularly and check for restrictions that can cause overheating or “no flow” shutdowns. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"1ij1gwv\" data-start=\"350\" data-end=\"535\"\u003eMaintain balanced water chemistry (pH, alkalinity, calcium hardness) to prevent scale buildup on the 5.5kW heating element and extend lifespan. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"lmwlwr\" data-start=\"536\" data-end=\"697\"\u003eNever run the heater dry or allow airlocks in the plumbing—bleed air after refills or service to avoid dry-fire damage. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"fvuc3k\" data-start=\"698\" data-end=\"818\"\u003eInspect electrical connections, sensors, and terminals periodically for tightness, corrosion, or heat discoloration.\u003c\/li\u003e\n\u003cli data-section-id=\"1hmsi7l\" data-start=\"819\" data-end=\"959\"\u003eUse a properly rated 30A GFCI supply and protect the system from voltage spikes or unstable power. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"1419pw7\" data-start=\"960\" data-end=\"1071\" data-is-last-node=\"\"\u003eAfter servicing, confirm correct mode\/settings so the auxiliary heater engages properly during demand cycles.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"MASTER SPAS","offers":[{"title":"Default Title","offer_id":45804703645887,"sku":"X300939","price":336.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0683\/5703\/0079\/files\/x300939-340x200.jpg?v=1782928598","url":"https:\/\/se0yig-03.myshopify.com\/products\/auxiliary-slave-heater-pack-5-5kw-x300939","provider":"Your Outdoor Setup Starts Here","version":"1.0","type":"link"}