Mixing Valve Types, Brands and Applications
Most mixing valves can be categorized into those used for whole-house applications, where mixing valve is installed in proximity to the hot water heater and those used directly at the plumbing fixture (point-of-use applications). The former must comply with ASSE 1017 for domestic applications and the later also with ASSE 1070 for point-of-use applications, including commercial settings (restaurant, hospitals, etc.). If used for drinking water purposes, these valves must also meet the NSF 61 criteria for low lead content in order to comply with 2014 SDWA.
Mixing valves used in hydronic heating (non-potable water) applications do not require ASSE or NSF approvals.
Mixing Valve Comparison
|Taco series||Honeywell series|
|5000||5100||AM-1||AM-1 “C”||AM-1 “C1070”||AM-1 “R”|
|Application||Anti-scald, hydronic heating||Anti-scald (point-of-use)||Anti-scald, hydronic heating||Anti-scald||Anti-scald (point-of-use) ||Hydronic heating only|
|ASSE Approvals||1017||1017, 1070||1017||1017||1017, 1070||-|
|Output range °F||85-175°F||85-120°F||70-145°F||70-120°F||70-120°F||70-180°F|
|Connections||Union Sweat, Union Threaded||Threaded, Union Sweat, Union Threaded|
Thermostatic Mixing Valves
Thermostatic mixing valve is a general term used to describe a 3-way valve which mixes the hot and cold water and provides constant temperature water at the outlet. The valve normally has a lockable dial knob which allows user to select and “lock-in” the desired output temperature. This temperature is usually 120°F for anti-scald applications and can go up to 180°F for hydronic heating applications.
In potable water and anti-scald applications, thermostatic mixing valve protects the homeowner against burns while maintaining a relatively high temperature inside the hot water heater or storage tank to prevent growth of Legionella.
In hydronic radiant heating, the valve is used to maintain a desired water temperature inside the PEX circuits for optimal energy efficiency and heat distribution.
The purpose of an anti-scald valve is to prevent hot water burns caused by fluctuations in hot or cold water pressure. Each year, thousands of scald cases are reported, with prevailing majority occurring in home. When water temperature at the plumbing fixture (such as a tub, shower or sink) suddenly changes, the user is subjected to thermal shock, instinctively trying to move away from the water source. Slow or lack of reaction could cause severe burns, while quick reactions present the risk of slips and falls.
An anti-scald valve, properly installed at the hot water source (hot water heater or a faucet), detects sudden changes in outlet water temperature and immediately shuts of the water if the temperature exceeds 120°F, protecting the user.
Taco Mixing Valves
Taco 5000 series valves are ASSE 1017 approved thermostatic mixing valves which can be used both as anti-scald valves and mixing valves for hydronic heating applications. 5000 series has a 175°F outlet temperature limit and allows for up to 20GPM flow.
Taco 5100 series valves are dual ASSE 1017 and 1070 approved mixing valves designed exclusively for scald protection purposes. These valves are approved for both residential and commercial settings, have a 120°F limit and allow for up to 14GPM flow.
Both series are “low-lead” compliant and are approved for potable water use.
Honeywell Mixing Valves
Honeywell AM-1 series thermostatic mixing valves have a dual ASSE 1017 and 1070 approval and have various, model-specific outlet temperature ratings. These valves are suitable for both residential (whole-house) and commercial (point-of-use) applications and meet the 2014 SDWA “low-lead” criteria.
Note: AM-1 “R” series valves (models with letter “R” in SKU#) are intended for use in heating applications only and cannot be used as anti-scald valves or for drinking water purposes.