The Caleffi 644250A is a 2-Way motorized ball zone valve with 3/4" Male NPT connections.
Best for zones needing low pressure drop and positive shutoff, including larger branches and snowmelt loops.
Specifications sourced from Caleffi North America technical literature. Last reviewed July 2026.
Key Features
Full-Port Ball Design
A ball closure gives a full-port, low-pressure-drop design when open and tight shutoff when closed, unlike a characterized globe seat.
Motorized Actuation
A synchronous motor drives the ball open and closed on a thermostat signal, with an auxiliary end switch available for pump or boiler interlock.
Auxiliary End Switch
An auxiliary microswitch rated 5 A at 24 V confirms valve position for pump or boiler interlock.
Technical Specifications
| Product Type | Motorized Ball Zone Valve |
| Connection Size | 3/4" |
| Connection Type | Male NPT |
| Configuration | 2-Way |
| Medium temperature range | 20-230 °F |
| Electric supply | 24 V AC |
| Power consumption at full capacity | 4 VA |
| Auxiliary microswitch contact rating (24 V) | 5 A |
| closing delta p max. | 150 psi |
| Series | 2-Way |
| Shipping Weight | 2.3 lb |
Documentation
Related Products
- Caleffi 644256A : Motorized Ball Valve 2-Way 3/4" Press
- Caleffi 644259A : Motorized Ball Valve 2-Way 3/4" Sweat
- Caleffi 644260A : Motorized Ball Valve 2-Way 1" Male NPT
- Caleffi 644266A : Motorized Ball Valve 2-Way 1" Press
Frequently Asked Questions
What does Caleffi 644250A do?
It is a motorized ball zone valve. A motor drives a full-port ball open and closed on a thermostat call, giving very low pressure drop when open and tight shutoff when closed.
How is Caleffi 644250A different from a thermo-electric zone valve?
A ball valve gives a full-port, low-pressure-drop path and positive shutoff, and suits larger zones. A thermo-electric valve is smaller and silent but has a characterized seat with higher pressure drop.
What connection does Caleffi 644250A use?
It is supplied with 3/4" Male NPT connections. Other sizes and connection styles in the range are listed under Related Products.
What supply voltage does Caleffi 644250A require?
Electric supply is 24 V AC, drawing 4 VA at full capacity.
What is the warranty on Caleffi 644250A?
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 Type:
- Motorized Ball Zone Valve
- Product Family:
- Motorized Ball Zone Valves
- Series:
- 2-Way
- Connection Type:
- Male NPT
- Connection Size:
- 3/4 inch
- Configuration:
- 2-Way
- Electric Supply:
- 24 V AC
- Medium Temperature Range:
- 20-230 deg F