The Caleffi NA553379 is a boiler trim kit with 1-1/4 in sweat connections, packaging an AutoFill automatic filling valve, a ASSE 1012 backflow preventer and a 4.4-gallon expansion tank to trim out a new boiler installation.
Product data compiled from Caleffi North America technical documentation. Last reviewed July 2026.
Key Features
Complete Boiler Trim
One kit trims out the boiler: AutoFill automatic filling valve, backflow preventer and expansion tank.
ASSE 1012 Backflow Preventer
Includes an ASSE 1012 dual-check backflow preventer with atmospheric vent for typical residential boiler feed.
4.4-Gallon Expansion Tank
A pre-pressurized diaphragm expansion tank absorbs the expansion volume of the heated system fluid.
Fewer Joints, Faster Install
Factory-matched components cut sourcing time and field assembly on new boiler installations.
Technical Data
| Function | Boiler trim kit (filling valve, backflow preventer, expansion tank) |
|---|---|
| ASSE listing | ASSE 1012 |
| Connection | 1-1/4 in sweat |
| Expansion tank | 4.4 gallon |
Documentation
Technical brochureRelated Products
Frequently Asked Questions
An AutoFill automatic filling valve, a backflow preventer and a 4.4-gallon pre-pressurized expansion tank - the trim components for a new boiler installation.
An ASSE 1012 dual-check with atmospheric vent for typical residential boiler feed.
4.4 gallons, pre-pressurized, sized for typical residential boiler applications.
- Type:
- Boiler Trim Kit
- ASSE Standard:
- ASSE 1012
- Connection Type:
- Sweat
- Connection Size:
- 1-1/4 in
