{"id":3224,"date":"2013-10-28T10:46:39","date_gmt":"2013-10-28T14:46:39","guid":{"rendered":"https:\/\/www.modernpi.com\/blog\/?p=3224"},"modified":"2025-09-10T17:00:37","modified_gmt":"2025-09-10T21:00:37","slug":"plumbing-question-what-is-a-mixing-valve","status":"publish","type":"post","link":"https:\/\/www.modernpi.com\/blog\/plumbing-service\/plumbing-question-what-is-a-mixing-valve\/","title":{"rendered":"Plumbing Question: What Is a Mixing Valve?"},"content":{"rendered":"<p>Updated On: September 10th 2025<\/p>\n<p><span style=\"font-weight: 400;\">You use running water in your home every day. When you reach for the knobs or handle that controls the flow of water into a sink, shower, or bathtub, you have the option to get cold or hot water, or a blend of both. You probably know the exact combination of the two that\u2019s the most pleasant for you.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">But did you know that there\u2019s a hidden mechanism in your plumbing to make <\/span><span style=\"font-weight: 400;\">sure<\/span><span style=\"font-weight: 400;\"> that you don\u2019t get an unpleasant surprise of extremely hot <\/span><span style=\"font-weight: 400;\">water? It\u2019s<\/span><span style=\"font-weight: 400;\"> called the <\/span><span style=\"font-weight: 400;\">mixing valve<\/span><span style=\"font-weight: 400;\">, and without<\/span><span style=\"font-weight: 400;\"> it,<\/span><span style=\"font-weight: 400;\"> your daily supply of water could become dangerous.<\/span><\/p>\n<h2><span style=\"font-weight: 400;\">What is a Mixing Valve and How Do They Work<\/span><span style=\"font-weight: 400;\">?<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">The term \u201c<\/span><span style=\"font-weight: 400;\">mixing valve<\/span><span style=\"font-weight: 400;\">\u201d has the general application of meaning any device in plumbing that controls the mix of hot and cold <\/span><span style=\"font-weight: 400;\">water. While this provides a comfortable temperature,<\/span><span style=\"font-weight: 400;\"> in most cases, a <\/span><span style=\"font-weight: 400;\">mixing valve<\/span><span style=\"font-weight: 400;\"> isn\u2019t designed simply for comfort; it serves as a critical safety mechanism that will keep you from accidental scalding due to high temperatures.<\/span><\/p>\n<h2><span style=\"font-weight: 400;\">How a <\/span><span style=\"font-weight: 400;\">Mixing Valve<\/span><span style=\"font-weight: 400;\"> Protects Your Family<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">The danger of scalding water from your plumbing exists because water in a home needs to be stored at high temperatures <\/span><span style=\"font-weight: 400;\">(often 120\u00b0F or more)<\/span><span style=\"font-weight: 400;\"> to prevent bacterial growth. Without the regulation of a <\/span><span style=\"font-weight: 400;\">mixing valve<\/span><span style=\"font-weight: 400;\">, this water might flow directly from <\/span><span style=\"font-weight: 400;\">your shower head or faucet <\/span><span style=\"font-weight: 400;\">and cause you injury.<\/span><\/p>\n<h2><span style=\"font-weight: 400;\">Types of Mixing Valves: <\/span><span style=\"font-weight: 400;\">Thermostatic vs. Pressure Balance<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">While they serve a similar purpose, there are two main types of valves used in modern plumbing systems:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Thermostatic Mixing Valves<\/b><b> (TMVs):<\/b><span style=\"font-weight: 400;\"> These valves use a thermostat to sense and control the water temperature. They automatically adjust the mix of hot and cold water to maintain a constant temperature, even if the pressure or temperature of the incoming water supply changes. These are often used for whole-home systems or in high-use areas like master showers.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Pressure Balance Valves<\/b><b>:<\/b><span style=\"font-weight: 400;\"> This is the most common type found in modern showers and bathtubs. It works by sensing the pressure ratio of hot to cold water. If there&#8217;s a sudden drop in cold water pressure (like when a toilet is flushed), the valve immediately reduces the hot water pressure to match, preventing a surge of scalding water. It maintains the <\/span><i><span style=\"font-weight: 400;\">balance<\/span><\/i><span style=\"font-weight: 400;\"> of pressure, not a specific temperature.<\/span><\/li>\n<\/ul>\n<h2><span style=\"font-weight: 400;\">4 Common Signs of a Failing <\/span><span style=\"font-weight: 400;\">Mixing Valve<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">Like any mechanical part, a <\/span><span style=\"font-weight: 400;\">mixing valve<\/span><span style=\"font-weight: 400;\"> can wear out over time. If you notice any of these issues, it&#8217;s a strong sign that your valve needs professional attention:<\/span><\/p>\n<ol>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Extreme Temperature Fluctuations:<\/b><span style=\"font-weight: 400;\"> The water temperature fluctuates wildly, from very hot to very cold, without you touching the handle.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Loss of Water Pressure:<\/b><span style=\"font-weight: 400;\"> A blocked or failing valve can restrict water flow to the faucet or shower.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>The Handle is Stuck or Leaking:<\/b><span style=\"font-weight: 400;\"> You can&#8217;t turn the handle, or you see water dripping from around the handle plate.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Only Hot or Cold Water:<\/b><span style=\"font-weight: 400;\"> The valve is stuck on one side and no longer blends water properly.<\/span><\/li>\n<\/ol>\n<h2><span style=\"font-weight: 400;\">Trust Your Plumbing to the Professionals<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">Because a <\/span><span style=\"font-weight: 400;\">mixing valve<\/span><span style=\"font-weight: 400;\"> is <\/span><span style=\"font-weight: 400;\">so<\/span><span style=\"font-weight: 400;\"> important for protecting you and your family, whether showering, <\/span><span style=\"font-weight: 400;\">doing the<\/span><span style=\"font-weight: 400;\"> dishes, or washing your hands, you need to take good care of your plumbing.\u00a0 If you&#8217;re experiencing any of the issues above, it&#8217;s time to call a professional.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The licensed plumbers at Modern Plumbing Industries have the expertise to inspect, repair, and replace all types of <\/span><span style=\"font-weight: 400;\">mixing valves<\/span><span style=\"font-weight: 400;\">. A visit from one of our local plumbing professionals will ensure your system is safe and provide peace of mind. You can<\/span><a href=\"https:\/\/www.modernpi.com\/contact\/schedule-service\"><span style=\"font-weight: 400;\"> fill out our form<\/span><\/a><span style=\"font-weight: 400;\"> to have a member of our team get in touch with you about scheduling an inspection or repair.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>You use running water in your home every day. When you reach for the knobs or handle that controls the flow of water into a sink, shower, or bathtub, you have the option to get cold or hot water, or a blend of both.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[176],"tags":[307,80,36],"_links":{"self":[{"href":"https:\/\/www.modernpi.com\/blog\/wp-json\/wp\/v2\/posts\/3224"}],"collection":[{"href":"https:\/\/www.modernpi.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.modernpi.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.modernpi.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.modernpi.com\/blog\/wp-json\/wp\/v2\/comments?post=3224"}],"version-history":[{"count":7,"href":"https:\/\/www.modernpi.com\/blog\/wp-json\/wp\/v2\/posts\/3224\/revisions"}],"predecessor-version":[{"id":5184,"href":"https:\/\/www.modernpi.com\/blog\/wp-json\/wp\/v2\/posts\/3224\/revisions\/5184"}],"wp:attachment":[{"href":"https:\/\/www.modernpi.com\/blog\/wp-json\/wp\/v2\/media?parent=3224"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.modernpi.com\/blog\/wp-json\/wp\/v2\/categories?post=3224"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.modernpi.com\/blog\/wp-json\/wp\/v2\/tags?post=3224"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}