Taco 5000 Series

Taco mixing valves are thermostatic mixing and diverting valves designed for domestic hot water distribution, radiant heating systems, and point-of-use tempering applications where a stable, code-compliant outlet temperature is required. The Taco mixing valve lineup includes the Series 5000 and 5120 ASSE 1017-listed valves for whole-system domestic hot water applications, the Series 5121 ASSE 1070-listed compact valve for point-of-use tempering, and the iSeries motorized valves for outdoor reset and setpoint control in hydronic radiant systems. Taco Series 5000 valves deliver a stable mixed water temperature across an extended range of 85°F to 176°F, and the Series 5121 carries a factory-set outlet temperature of 110°F with an accuracy of +/-3°F. For plumbing contractors and hydronic system designers, Taco mixing valves address Legionella control by allowing water heater storage above 140°F while delivering blended water at 120°F or below at distribution points.

Series 5000 Mixing Valves (ASSE 1017)

The Taco Series 5000 is a lead-free thermostatic mixing valve rated to ASSE 1017, designed for domestic hot water distribution in residential and light commercial applications. Series 5000 valves function as both mixing and diverting valves and provide fail-safe shut-off on either hot or cold water supply failure. The 5000 Series delivers a stable mixed water temperature across an extended range of 85°F to 176°F, with the valve body factory set at 105°F to 115°F at a 150°F hot water inlet temperature, per SupplyHouse product listing. Connection options include 3/4" sweat, 3/4" press, 1/2" press, and union sweat configurations, with optional integral gauge.

Series 5120 High-Flow Mixing Valves (ASSE 1017)

The Taco Series 5120 is an NSF 61 and ASSE 1017-listed high-flow mixing valve for domestic hot water distribution, with low headloss and high flow capacity suitable for systems with large variations in flow rate and supply conditions. The 5120 Series is available in 3/4" sweat union configuration (model 5123-C2) and covers an extended mix temperature range of 85°F to 176°F, per SupplyHouse product listings. The 5120 series accepts connection in sweat, NPT, PEX, and CPVC union configurations. An optional outlet temperature strip and dial gauge adapter are available accessories for this series.

Series 5121 Point-of-Use Mixing Valves (ASSE 1070)

The Taco Series 5121 is a compact thermostatic mixing valve listed to ASSE 1070, CAS B125.3, and NSF 61 for point-of-use tempering applications where an ASSE 1070 valve is required by code, including hospitals, schools, nursing homes, and public facilities. The 5121 Series is factory set to 110°F (43.3°C) with an accuracy of +/-3°F, an outlet temperature range of 95°F to 118°F, and a maximum flow of 5.8 GPM, per SupplyHouse product listing. The 5121 accepts a hot supply temperature of 120°F to 180°F and a cold supply temperature of 39°F to 85°F, with a maximum inlet pressure of 230 PSI.

iSeries Motorized Mixing Valves

The Taco iSeries mixing valves are motorized, electronically controlled thermostatic valves designed for outdoor reset and fixed setpoint control in radiant heating and hydronic distribution applications. iSeries valves are available in 3/4" and 1" sizes with sweat or NPT connection and setpoint or outdoor reset control configurations. Outdoor reset iSeries valves include a compatible outdoor sensor (part 9300-2052RP) sold separately and an outdoor reset actuator head (part IT024Q6A1). The iSeries platform allows supply water temperature to the radiant circuit to modulate based on outdoor conditions, improving system efficiency and floor comfort relative to fixed-temperature mixing.

How to Choose Taco Mixing Valves

The first selection variable is the ASSE listing required for the application. ASSE 1017 covers master mixing valves for domestic hot water distribution from a water heater or storage tank to multiple fixtures. ASSE 1070 covers point-of-use tempering valves at individual fixtures, lavatory faucets, or emergency fixtures. Checking the plumbing code requirement for the specific application before specifying a mixing valve avoids a non-compliant installation.

Connection type and pipe size are the next selection variables. Taco mixing valves are available in 1/2" and 3/4" nominal pipe sizes with sweat, press, NPT, PEX, and CPVC union connection options. The correct connection type must match the existing or planned pipe material in the system. Union sweat connections allow the valve body to be replaced without cutting into the piping.

For radiant heating applications, the iSeries motorized mixing valve is the correct specification when outdoor reset control is required. The iSeries setpoint valve provides fixed mixed water temperature, while the outdoor reset version modulates supply temperature based on an outdoor air sensor, reducing supply temperature during mild weather for improved floor temperature control and lower energy consumption.

For anyone asking how Taco mixing valves address Legionella risk: the ASSE 1017 listing allows hot water storage at temperatures above 140°F to inhibit Legionella growth, while the mixing valve blends hot and cold to deliver 120°F or below at the distribution manifold. This combination of high storage temperature with tempered delivery is the code-recognized approach to Legionella control in domestic hot water systems.

FAQs

What is the difference between Taco Series 5000 ASSE 1017 and Series 5121 ASSE 1070 mixing valves?
The Taco Series 5000 is listed to ASSE 1017, which covers master mixing valves installed at the water heater or storage tank outlet for whole-building domestic hot water distribution. The Series 5121 is listed to ASSE 1070, which covers point-of-use tempering valves installed at individual fixtures or use points where a dedicated local tempered water supply is required by code. The two certifications address different installation locations and code requirements.

What temperature range does the Taco Series 5000 mixing valve cover?
The Taco Series 5000 mixing valve covers a mix temperature range of 85°F to 176°F, per Taco product documentation on SupplyHouse. The valve body is factory set at 105°F to 115°F at a 150°F hot water inlet temperature. The Series 5000 is ASSE 1017 listed and suitable for domestic hot water distribution, radiant applications, and installations requiring tightly controlled water temperature.

What is the maximum flow rate of the Taco 5121 point-of-use mixing valve?
The Taco Series 5121 point-of-use mixing valve has a maximum flow rate of 5.8 GPM and a minimum flow rate of 0.34 GPM, per SupplyHouse product listing. The 5121 accepts a hot supply temperature range of 120°F to 180°F and a cold supply range of 39°F to 85°F. Maximum inlet pressure is 230 PSI.

What connection types are available for Taco Series 5000 and 5120 mixing valves?
Taco Series 5000 and 5120 mixing valves are available in sweat, press, NPT, PEX, and CPVC union connection configurations in 1/2" and 3/4" nominal pipe sizes, per Taco product documentation. The 3/4" sweat union configuration with integral gauge (model 5003-C3-G) and the 3/4" press configuration with gauge (5003-H3-G) are both available on SupplyHouse.

What is the Taco iSeries mixing valve used for?
The Taco iSeries mixing valve is a motorized electronically controlled mixing valve used in radiant heating and hydronic distribution systems requiring outdoor reset or fixed setpoint supply water temperature control. The iSeries outdoor reset configuration uses an outdoor air sensor (sold separately, part 9300-2052RP) to modulate the mixed supply water temperature to the radiant circuit based on outdoor conditions, reducing supply temperature during mild weather.