The Caleffi 521608A is a MixCal thermostatic mixing valve with 1" PEX Expansion 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 NA technical literature, 2025 revisions.
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.
Fast Mechanical Connection
PEX Expansion tailpieces cut installation time and remove open flame from the job site.
Technical Specifications
| Connection Size | 1" |
| Connection Type | PEX Expansion |
| Configuration | 3-Way |
| Maximum operating pressure | 200 psi |
| Adjustment temperature range | 85 - 150 deg F |
| Maximum inlet temperature | 200 deg F |
| Flow rate working range | 1.0 - 14 gpm |
| Material | DZR low lead brass |
| Certification | ASSE 1017 |
| Series | MixCal |
| Valve Technology | Thermostatic |
| Shipping Weight | 2.4 lb |
Documentation
Design Resources
Related Products
- Caleffi 521600A : MixCal 3-Way Thermostatic Mixing Valve 1" NPT
- Caleffi 521600AC : MixCal 3-Way Thermostatic Mixing Valve 1" NPT
- Caleffi 521606A : MixCal 3-Way Thermostatic Mixing Valve 1" Press
- Caleffi 521606AC : MixCal 3-Way Thermostatic Mixing Valve 1" Press
Frequently Asked Questions
Is Caleffi 521608A approved for point-of-distribution service?
Yes. Caleffi 521608A 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 521608A?
The adjustment temperature range is 85 - 150 deg F. Maximum inlet temperature is 200 deg F. Confirm the setpoint against the applicable plumbing code for the installation.
What connection does Caleffi 521608A use?
Caleffi 521608A is supplied with 1" PEX Expansion connections. Other connection styles in the MixCal family are listed under Related Products.
Does Caleffi 521608A 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 521608A?
Caleffi covers this product under its standard two-year limited warranty against defects in material and workmanship from the date of purchase. ZOT Supply is an authorized Caleffi distributor.
- Product Series:
- MixCal
- Valve Technology:
- Thermostatic
- Application:
- Point of Distribution
- Connection Type:
- PEX Expansion
- Connection Size:
- 1 inch
- ASSE Listing:
- ASSE 1017
- Integral Check Valves:
- No
- Temperature Gauge:
- No
- Adjustment Temperature Range:
- 85 - 150 deg F
- Body Material:
- DZR low lead brass