The Caleffi 521500A is a MixCal thermostatic mixing valve with 3/4" NPT connections, listed to ASSE 1017. It is used for point of distribution temperature control in domestic hot water and hydronic systems.
Best for water heater and storage tank outlets where a single valve sets the distribution temperature for an entire building, zone or riser.
Specifications sourced from Caleffi North America document 01050_NA. Last reviewed August 2026.
Key Features
ASSE 1017 Listed
Certified for point-of-distribution service, controlling water heater outlet temperature for an entire building or zone.
Thermostatic Element Control
A wax-actuated element responds to outlet temperature changes and repositions the shuttle continuously, holding setpoint without power or controls.
Low-Lead Brass Construction
Wetted surfaces carry a weighted average lead content below 0.25%, meeting Section 1417 of the Safe Drinking Water Act.
Technical Specifications
| Connection Size | 3/4" |
| Connection Type | Male NPT union |
| Configuration | 3-Way |
| Maximum operating pressure | 200 psi |
| Adjustment temperature range | 85 - 150 °F |
| Maximum inlet temperature | 200 °F |
| Flow rate working range | 1.0 - 14 gpm |
| Material | low lead brass (<0.25% lead content) |
| Certification | ASSE 1017 |
| Series | MixCal |
| Valve Technology | Thermostatic |
| Shipping Weight | 2.0 lb |
Documentation
Design Resources
Related Products
- Caleffi 521500AC : MixCal 3-Way Thermostatic Mixing Valve 3/4" NPT w/ Inlet Checks
- Caleffi 521506A : MixCal 3-Way Thermostatic Mixing Valve 3/4" Press
- Caleffi 521506AC : MixCal 3-Way Thermostatic Mixing Valve 3/4" Press w/ Inlet Checks
- Caleffi 521507A : MixCal 3-Way Thermostatic Mixing Valve 3/4" PEX Crimp
Frequently Asked Questions
Is Caleffi 521500A approved for point-of-distribution service?
Yes. Caleffi 521500A is listed to ASSE 1017, the standard covering temperature-actuated mixing valves used to control hot water distribution from a water heater or storage tank. ASSE 1017 valves regulate system supply temperature; they are not a substitute for ASSE 1070 point-of-use scald protection at individual fixtures.
What is the temperature adjustment range of Caleffi 521500A?
The adjustment temperature range is 85 - 150 °F. Maximum inlet temperature is 200 °F. Confirm the setpoint against the applicable plumbing code for the installation.
What connection does Caleffi 521500A use?
Caleffi 521500A is supplied with 3/4" NPT connections. Other connection styles in the MixCal family are listed under Related Products.
Does Caleffi 521500A include integral check valves?
No. This model is supplied without integral inlet check valves. Caleffi offers a companion model with a C in the product code for applications that require built-in crossflow protection.
What is the warranty on Caleffi 521500A?
Caleffi covers this product under its standard two-year limited warranty against defects in material and workmanship from the date of shipment. ZOT Supply is an authorized Caleffi distributor.
- Product Series:
- MixCal
- Valve Technology:
- Thermostatic
- Application:
- Point of Distribution
- Connection Type:
- Male NPT
- Connection Size:
- 3/4 inch
- ASSE Listing:
- ASSE 1017
- Integral Check Valves:
- No
- Temperature Gauge:
- No
- Adjustment Temperature Range:
- 85 - 150 deg F
- Body Material:
- Low Lead Brass
