{"id":1395,"date":"2018-07-26T13:06:12","date_gmt":"2018-07-26T13:06:12","guid":{"rendered":"http:\/\/woodenhottubsale.co.uk\/blog\/?p=1395"},"modified":"2026-01-14T08:33:51","modified_gmt":"2026-01-14T08:33:51","slug":"fill-empty-hot-tub","status":"publish","type":"post","link":"https:\/\/www.woodenhottubsale.co.uk\/blog\/fill-empty-hot-tub\/","title":{"rendered":"Filling And Draining an Outdoor Hot Tub, how?"},"content":{"rendered":"<article>Filling and draining a <a href=\"https:\/\/www.woodenhottubsale.co.uk\/hot-tubs\/wood-fired-hot-tubs\/\" target=\"_blank\" rel=\"noopener\">hot tub<\/a> sounds simple, but doing it the right way protects your equipment, extends component life, and keeps your water safe. Follow this guide for the best results, including water-level tips, priming the system, safe draining, and winterizing. For routine upkeep, see our <a href=\"https:\/\/www.woodenhottubsale.co.uk\/maintenance-of-wooden-hot-tub\/\" target=\"_self\" rel=\"internal noopener\">hot tub maintenance checklist<\/a>.<br \/><!--more-->\n<figure><img decoding=\"async\" src=\"https:\/\/www.woodenhottubsale.co.uk\/blog\/wp-content\/uploads\/2018\/07\/fill_flow.png\" alt=\"Flow diagram showing the correct hot tub filling sequence\" \/>\n<figcaption>Hot tub filling: rinse \u2192 hose + prefilter \u2192 fill slowly \u2192 purge air \u2192 leak check \u2192 heat only when jets are covered.<\/figcaption>\nBefore You Start<\/figure>\n<ul>\n<li>Power <strong>OFF<\/strong> at the breaker or isolation switch.<\/li>\n<li>Confirm the <strong>drain valve is closed<\/strong> and caps are seated.<\/li>\n<li>Check the <strong>filter basket<\/strong> is clean and correctly fitted.<\/li>\n<\/ul>\n<h2>How to Fill a Hot Tub<\/h2>\n<ol>\n<li><strong>Rinse and inspect:<\/strong> Remove leaves and grit. Rinse the shell and wipe dry around unions and valves.<\/li>\n<li><strong>Attach hose + prefilter:<\/strong> Prefilters help if you have hard water or sediment.<\/li>\n<li><strong>Fill slowly:<\/strong> Watch for drips at fittings. Stop if leaks appear and reseat the joint.<\/li>\n<li><strong>Set water level:<\/strong> Keep water just above the highest jets so intakes stay covered.<\/li>\n<li><strong>Prime circulation:<\/strong> Open air valves for a few seconds to purge air, then close and start the pump.<\/li>\n<li><strong>Balance &amp; sanitize:<\/strong> Adjust pH (7.2\u20137.8) and alkalinity. Add non-foaming sanitizer and start heating (compare systems in <a href=\"https:\/\/www.woodenhottubsale.co.uk\/hot-tub-water-care-options\/\" target=\"_self\" rel=\"internal noopener\">hot tub water care options<\/a>).<\/li>\n<\/ol>\n<figure><img decoding=\"async\" src=\"https:\/\/www.woodenhottubsale.co.uk\/blog\/wp-content\/uploads\/2018\/07\/water_level_guide.png\" alt=\"Hot tub water level guide relative to seats and jets\" \/>\n<figcaption>Maintain the recommended water band: too low causes air intake; too high risks spills and poor skimming.<\/figcaption>\n<\/figure>\n<h2>How to Empty \/ Drain a Hot Tub<\/h2>\n<p>Always power the unit off before draining. Use the built-in drain valve or a submersible pump. Direct water to a safe runoff or sewer\u2014avoid flooding the foundation or garden beds.<\/p>\n<figure><img decoding=\"async\" src=\"https:\/\/www.woodenhottubsale.co.uk\/blog\/wp-content\/uploads\/2018\/07\/drain_schematic.png\" alt=\"Schematic of hot tub drain valve with hose routed to a safe runoff point\" \/>\n<figcaption>Gravity drain schematic: connect a hose to the drain and route to an approved runoff point.<\/figcaption>\n<\/figure>\n<h2>Winterizing (If Not in Use)<\/h2>\n<ul>\n<li>Power off. <strong>Fully drain<\/strong> the tub.<\/li>\n<li><strong>Blow out lines<\/strong> with a wet\/dry vacuum.<\/li>\n<li>Open <strong>all drain caps<\/strong>, remove residual water, and <strong>dry the shell<\/strong>.<\/li>\n<li>Fit a tight <strong>insulated cover<\/strong>. Check monthly for water ingress.<\/li>\n<\/ul>\n<figure><img decoding=\"async\" src=\"https:\/\/www.woodenhottubsale.co.uk\/blog\/wp-content\/uploads\/2018\/07\/winterize_steps.png\" alt=\"Checklist diagram for winterizing a hot tub\" \/>\n<figcaption>Winterizing checklist: power off \u2192 drain \u2192 blow out lines \u2192 open drains &amp; plugs \u2192 dry shell \u2192 cover \u2192 monthly checks.<\/figcaption>\n<\/figure>\n<h2>Key Safety Reminders<\/h2>\n<ul>\n<li>Never run the heater <strong>without water flow<\/strong>.<\/li>\n<li>Keep children and pets away while filling or draining.<\/li>\n<li>Use non-slip footwear; wet decks are slippery.<\/li>\n<li>Dispose of drained water responsibly; follow local rules.<\/li>\n<\/ul>\n<h2>Conclusion<\/h2>\n<p>With the right sequence\u2014rinse, fill, prime, balance, and careful draining\u2014you\u2019ll protect pumps, heaters, and fittings while keeping water clear and safe.<\/p>\n<h2 data-start=\"151\" data-end=\"211\">Frequently Asked Questions \u2013 Filling &amp; Draining a Hot Tub<\/h2>\n<p data-start=\"213\" data-end=\"462\"><strong data-start=\"213\" data-end=\"283\">Should I turn off the power before filling or draining my hot tub?<\/strong><br data-start=\"283\" data-end=\"286\" \/>Yes. Always switch the power <strong data-start=\"315\" data-end=\"357\">OFF at the breaker or isolation switch<\/strong> before filling or draining. Running pumps or heaters without proper water flow can cause serious damage.<\/p>\n<p data-start=\"464\" data-end=\"687\"><strong data-start=\"464\" data-end=\"513\">What water level should I fill my hot tub to?<\/strong><br data-start=\"513\" data-end=\"516\" \/>Water should sit <strong data-start=\"533\" data-end=\"564\">just above the highest jets<\/strong> so all intakes remain fully submerged. Too little water pulls in air; too much can cause spills and poor surface skimming.<\/p>\n<p data-start=\"689\" data-end=\"899\"><strong data-start=\"689\" data-end=\"740\">Why is it important to fill the hot tub slowly?<\/strong><br data-start=\"740\" data-end=\"743\" \/>Filling slowly allows you to <strong data-start=\"772\" data-end=\"816\">monitor for leaks at fittings and unions<\/strong>. If drips appear, stop filling immediately and reseat the joint before continuing.<\/p>\n<p data-start=\"901\" data-end=\"1137\"><strong data-start=\"901\" data-end=\"968\">Do I really need to prime the circulation system after filling?<\/strong><br data-start=\"968\" data-end=\"971\" \/>Yes. Air trapped in the pipes can prevent proper water flow. Briefly opening air valves and purging the system ensures the pump is fully primed before heating begins.<\/p>\n<p data-start=\"1139\" data-end=\"1313\"><strong data-start=\"1139\" data-end=\"1187\">When can I turn on the heater after filling?<\/strong><br data-start=\"1187\" data-end=\"1190\" \/>Only once <strong data-start=\"1200\" data-end=\"1270\">all jets are fully covered with water and circulation is confirmed<\/strong>. Never heat a tub without full water flow.<\/p>\n<p data-start=\"1315\" data-end=\"1482\"><strong data-start=\"1315\" data-end=\"1355\">How often should I drain my hot tub?<\/strong><br data-start=\"1355\" data-end=\"1358\" \/>Most hot tubs should be drained and refilled <strong data-start=\"1403\" data-end=\"1423\">every 3\u20134 months<\/strong>, depending on usage, sanitation method, and water quality.<\/p>\n<p data-start=\"1484\" data-end=\"1707\"><strong data-start=\"1484\" data-end=\"1530\">What is the safest way to drain a hot tub?<\/strong><br data-start=\"1530\" data-end=\"1533\" \/>Turn the power off, then use the <strong data-start=\"1566\" data-end=\"1612\">built-in drain valve or a submersible pump<\/strong>. Always route water to a safe runoff point or sewer\u2014never flood the foundation or garden beds.<\/p>\n<p data-start=\"1709\" data-end=\"1893\"><strong data-start=\"1709\" data-end=\"1752\">Can I drain hot tub water onto my lawn?<\/strong><br data-start=\"1752\" data-end=\"1755\" \/>Only if <strong data-start=\"1763\" data-end=\"1790\">local regulations allow<\/strong> and the water does not contain high chemical levels. Always follow local environmental disposal rules.<\/p>\n<p data-start=\"1895\" data-end=\"2152\"><strong data-start=\"1895\" data-end=\"1946\">How do I winterize a hot tub if I won\u2019t use it?<\/strong><br data-start=\"1946\" data-end=\"1949\" \/>Switch off power, <strong data-start=\"1967\" data-end=\"1990\">fully drain the tub<\/strong>, blow out all lines with a wet\/dry vacuum, open all drain caps, dry the shell completely, and secure a tight insulated cover. Check monthly for moisture ingress.<\/p>\n<p data-start=\"2154\" data-end=\"2320\"><strong data-start=\"2154\" data-end=\"2205\">Why must I blow out the pipes when winterizing?<\/strong><br data-start=\"2205\" data-end=\"2208\" \/>Even small amounts of trapped water can <strong data-start=\"2248\" data-end=\"2269\">freeze and expand<\/strong>, cracking pipes, heaters, and pumps during winter.<\/p>\n<p data-start=\"2322\" data-end=\"2514\"><strong data-start=\"2322\" data-end=\"2376\">Is it safe to leave a hot tub empty during winter?<\/strong><br data-start=\"2376\" data-end=\"2379\" \/>Yes\u2014if it is <strong data-start=\"2392\" data-end=\"2440\">properly drained, dried, and tightly covered<\/strong>. Poor winterizing is what causes freeze damage, not the empty tub itself.<\/p>\n<p data-start=\"2516\" data-end=\"2627\"><strong data-start=\"2516\" data-end=\"2597\">What are the biggest mistakes people make when filling or draining a hot tub?<\/strong><br data-start=\"2597\" data-end=\"2600\" \/>The most common errors are:<\/p>\n<ul data-start=\"2628\" data-end=\"2829\">\n<li data-start=\"2628\" data-end=\"2683\">\n<p data-start=\"2630\" data-end=\"2683\">Heating the tub before the jets are fully submerged<\/p>\n<\/li>\n<li data-start=\"2684\" data-end=\"2716\">\n<p data-start=\"2686\" data-end=\"2716\">Forgetting to prime the pump<\/p>\n<\/li>\n<li data-start=\"2717\" data-end=\"2757\">\n<p data-start=\"2719\" data-end=\"2757\">Draining without switching off power<\/p>\n<\/li>\n<li data-start=\"2758\" data-end=\"2794\">\n<p data-start=\"2760\" data-end=\"2794\">Skipping line blow-out in winter<\/p>\n<\/li>\n<li data-start=\"2795\" data-end=\"2829\">\n<p data-start=\"2797\" data-end=\"2829\">Disposing of water irresponsibly<\/p>\n<\/li>\n<\/ul>\n<p data-start=\"2831\" data-end=\"3050\"><strong data-start=\"2831\" data-end=\"2880\">Is a prefilter really necessary when filling?<\/strong><br data-start=\"2880\" data-end=\"2883\" \/>While not mandatory, a <strong data-start=\"2906\" data-end=\"2943\">prefilter is strongly recommended<\/strong> in hard-water areas or where sediment is present, as it reduces scale buildup and prolongs equipment life.<\/p>\n<p data-start=\"2831\" data-end=\"3050\">\u00a0<\/p>\n<\/article>\n\n\n<!-- Schema: FAQPage \u2013 Filling & Draining a Hot Tub -->\n<script type=\"application\/ld+json\">\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Should I turn off the power before filling or draining my hot tub?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. Always switch the power OFF at the breaker or isolation switch before filling or draining. Running pumps or heaters without proper water flow can cause serious damage.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What water level should I fill my hot tub to?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Water should sit just above the highest jets so all intakes remain fully submerged. Too little water pulls in air; too much can cause spills and poor surface skimming.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Why is it important to fill the hot tub slowly?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Filling slowly allows you to monitor for leaks at fittings and unions. If drips appear, stop filling immediately and reseat the joint before continuing.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Do I really need to prime the circulation system after filling?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. Air trapped in the pipes can prevent proper water flow. Briefly opening air valves and purging the system ensures the pump is fully primed before heating begins.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"When can I turn on the heater after filling?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Only once all jets are fully covered with water and circulation is confirmed. Never heat a tub without full water flow.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How often should I drain my hot tub?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Most hot tubs should be drained and refilled every 3\u20134 months, depending on usage, sanitation method, and water quality.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the safest way to drain a hot tub?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Turn the power off, then use the built-in drain valve or a submersible pump. Always route water to a safe runoff point or sewer\u2014never flood the foundation or garden beds.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can I drain hot tub water onto my lawn?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Only if local regulations allow and the water does not contain high chemical levels. Always follow local environmental disposal rules.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How do I winterize a hot tub if I won\u2019t use it?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Switch off power, fully drain the tub, blow out all lines with a wet\/dry vacuum, open all drain caps, dry the shell completely, and secure a tight insulated cover. Check monthly for moisture ingress.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Why must I blow out the pipes when winterizing?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Even small amounts of trapped water can freeze and expand, cracking pipes, heaters and pumps during winter.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is it safe to leave a hot tub empty during winter?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. If it is properly drained, dried and tightly covered. Poor winterizing is what causes freeze damage, not the empty tub itself.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What are the biggest mistakes people make when filling or draining a hot tub?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Heating the tub before the jets are fully submerged, forgetting to prime the pump, draining without switching off power, skipping line blow-out in winter, and disposing of water irresponsibly.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is a prefilter really necessary when filling?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"While not mandatory, a prefilter is strongly recommended in hard-water areas or where sediment is present, as it reduces scale buildup and prolongs equipment life.\"\n      }\n    }\n  ]\n}\n<\/script>\n","protected":false},"excerpt":{"rendered":"<p>Filling and draining a hot tub sounds simple, but doing it the right way protects your equipment, extends component life, and keeps your water safe. Follow this guide for the best results, including water-level tips, priming the system, safe draining, and winterizing. For routine upkeep, see our hot tub maintenance checklist.<\/p>\n","protected":false},"author":3,"featured_media":10218,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1138],"tags":[],"class_list":["post-1395","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hot-tub-guides"],"_links":{"self":[{"href":"https:\/\/www.woodenhottubsale.co.uk\/blog\/wp-json\/wp\/v2\/posts\/1395","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.woodenhottubsale.co.uk\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.woodenhottubsale.co.uk\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.woodenhottubsale.co.uk\/blog\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.woodenhottubsale.co.uk\/blog\/wp-json\/wp\/v2\/comments?post=1395"}],"version-history":[{"count":0,"href":"https:\/\/www.woodenhottubsale.co.uk\/blog\/wp-json\/wp\/v2\/posts\/1395\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.woodenhottubsale.co.uk\/blog\/wp-json\/wp\/v2\/media\/10218"}],"wp:attachment":[{"href":"https:\/\/www.woodenhottubsale.co.uk\/blog\/wp-json\/wp\/v2\/media?parent=1395"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.woodenhottubsale.co.uk\/blog\/wp-json\/wp\/v2\/categories?post=1395"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.woodenhottubsale.co.uk\/blog\/wp-json\/wp\/v2\/tags?post=1395"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}