Caleffi ZSR104 - Z-one™ Relay (four zone)

SKU: N-427
C$ 442
14 In Stock

Caleffi ZSR104 - Z-one™ Relay (four zone)


Caleffi Zone Relay ZSR104

The ZSR104 is a multi-zone pump and boiler operating control for multiple zone hydronic heating or cooling systems. The ZSR104 interfaces with low voltage thermostats, or any other low voltage controllers having a switching action. The ZSR104 controls up to 4 heating circulator pumps, a primary pump and has LED indicators to provide functional status and easy system troubleshooting.

ZSR106 Internals (ZSR104 is identical minus three zones)

Caleffi ZSR 106 internals


Compatible with low voltage 2, 3, or 4 wire thermostats
R, W, C and T T COM dual labeling at thermostat terminals
Z-oneLink™ unlimited zone expansion
120 VAC pump outputs
Remote Enable input 24 - 120 VAC
Selectable Priority with 1 hour time-out
Selectable Post Purge and Exercise
Dry contacts for ZONE 1 (DHW), capable of switching line voltage
High capacity transformer
Large terminal connections
Simplified wiring with extra ground terminals
Heavy duty sealed relays
All pumps fuse protected (with spare fuse)
Front LED Lights
100% Factory tested with 3 year warranty, ETL Approved

Multiple Thermostat Configuration

Caleffi ZSR 104 multiple thermostat diagram


  • Power supply: 120 VAC, 50/60 Hz
  • Transformer voltage: 24 VAC
  • Maximum transformer load: 12 VA
  • Electrical switch rating pump output: 120 VAC, 5A each (20A max combined)
  • Dry contact rating, Zone 1 ES, XX, AUX: 120 VAC max, 2A each
  • Replaceable fuses: Type 2AG, 5A slow blow
  • Working temperature range: 32°F (0°C)—115°F (45°C)
  • Maximum humidity: 90% non-condensing
  • Approvals: Conforms to UL873 / Certified to CSA C22 No 24, listed by ETL

ZSR10x Dimensions

Dimension (L x W x H) 12 x 12 x 4 Inch
Weight 2 Pound

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