{"id":5428,"date":"2026-11-10T18:04:36","date_gmt":"2026-11-10T18:04:36","guid":{"rendered":"https:\/\/305backyards.com\/?product=harvia-m3-sl-wood-fired-sauna-heater"},"modified":"2026-11-10T18:04:36","modified_gmt":"2026-11-10T18:04:36","slug":"harvia-m3-sl-wood-fired-sauna-heater","status":"publish","type":"product","link":"https:\/\/305backyards.com\/?product=harvia-m3-sl-wood-fired-sauna-heater","title":{"rendered":"Harvia M3 SL Wood-Fired Sauna Heater"},"content":{"rendered":"<p>The <strong>Harvia M3 SL Classic Wood-Fired Sauna Heater<\/strong>\u00a0is designed for sauna owners who prefer to load firewood <strong>from outside the sauna room<\/strong>. Its <strong>through-the-wall firebox<\/strong> allows the stove to be heated from an adjacent space or outdoors, helping keep the sauna interior clean, uncluttered, and comfortable during use.<\/p>\n<p>Well suited for <strong>small to medium-sized saunas<\/strong>, the M3 SL delivers reliable heat in a compact format. A <strong>glass furnace door<\/strong> provides a view of the flames, adding warmth and ambiance to the sauna experience, while the door\u2019s opening direction can be reversed to suit different installation layouts. For additional functionality, the stove can be paired with a <strong>Harvia pipe-mounted water heater<\/strong>, allowing you to heat water while enjoying your sauna.<\/p>\n<p>Built with durability and ease of installation in mind, the M3 SL reflects Harvia\u2019s focus on practical design. <strong>Adjustable legs<\/strong> (available on the 20-series) help ensure a stable setup, even on uneven floors, making installation straightforward and dependable.<\/p>\n<h3>Key Features<\/h3>\n<ul>\n<li>\n<p>Designed for sauna rooms <strong>212\u2013459 ft\u00b3 (6\u201313 m\u00b3)<\/strong><\/p>\n<\/li>\n<li>\n<p>Through-the-wall firebox for external or adjacent-room loading<\/p>\n<\/li>\n<li>\n<p>Graphite black finish with stainless steel airflow spoiler<\/p>\n<\/li>\n<li>\n<p>Glass door for fire visibility and added atmosphere<\/p>\n<\/li>\n<li>\n<p>Compatible with Harvia pipe model water heater<\/p>\n<\/li>\n<\/ul>\n<p>The <strong>Harvia M3 SL<\/strong> offers a traditional wood-fired sauna experience with added convenience\u2014ideal for layouts where external loading is preferred.<\/p>\n<p>Chimney pipe not included. Stones sold separately.<\/p>\n<p>\u00a0<\/p>\n<ul>\n<li>\n<p><strong>Model:<\/strong> WKM3SL<\/p>\n<\/li>\n<li>\n<p><strong>Power Output:<\/strong> 16.5 kW<\/p>\n<\/li>\n<li>\n<p><strong>Recommended Sauna Room Size:<\/strong> 212\u2013459 ft\u00b3 (6\u201313 m\u00b3)<\/p>\n<\/li>\n<li>\n<p><strong>Stone Capacity:<\/strong> 66 lb (30 kg), \u00d8 10\u201315 cm<\/p>\n<\/li>\n<li>\n<p><strong>Heater Dimensions:<\/strong> 15.4? W \u00d7 (17? + 8.7?) D \u00d7 28? H<br \/><em>(390 \u00d7 430 + 220 \u00d7 710 mm)<\/em><\/p>\n<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Harvia wood-burning sauna heater, for sauna rooms of 212\u2013459 ft\u00b3.<\/p>\n","protected":false},"featured_media":5255,"comment_status":"open","ping_status":"closed","template":"","meta":{"_monsterinsights_skip_tracking":false},"product_brand":[],"product_cat":[71],"product_tag":[],"class_list":["post-5428","product","type-product","status-publish","has-post-thumbnail","product_cat-sauna-heaters","first","instock","shipping-taxable","product-type-simple"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 5.0.1.1 - aioseo.com -->\n\t<meta name=\"description\" content=\"Harvia wood-burning sauna heater, for sauna rooms of 212\u2013459 ft\u00b3.\" \/>\n\t<meta name=\"robots\" content=\"noindex, nofollow, max-image-preview:large\" \/>\n\t<link rel=\"canonical\" href=\"https:\/\/305backyards.com\/?product=harvia-m3-sl-wood-fired-sauna-heater\" \/>\n\t<meta name=\"generator\" content=\"All in One SEO (AIOSEO) 5.0.1.1\" \/>\n\t\t<meta property=\"og:locale\" content=\"en_US\" \/>\n\t\t<meta property=\"og:site_name\" content=\"305 Backyards -\" \/>\n\t\t<meta property=\"og:type\" content=\"article\" \/>\n\t\t<meta property=\"og:title\" content=\"Harvia M3 SL Wood-Fired Sauna Heater - 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