304V - Hydronic Heating Zone Valve Control - Four Zones with Priority

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SKU: 304V
Regular price $205.44

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Tekmar 304V - Hydronic Heating Zone Valve Control - Four Zones with Priority

The Zone Valve Control 304V connects up to four thermostats and operates zone valves to provide heating to a zoned hydronic heating system. The 304V operates a system pump whenever a zone valve opens. Zone 1 can operate either a zone valve or a circulator to provide heat to an indirect domestic hot water tank with optional priority over zones 2 through 4. The 304V includes optional exercising to prevent circulator seizure when not in use, and optional post purge operation of the domestic hot water tank to maximize energy savings. The 304V provides a RoomResponse™ signal to modulating-condensing boilers to optimize comfort while improving boiler efficiency.


  • RoomResponse signal, compatible with all low voltage thermostats
  • Fuses protect transformers and pumps
  • Compatible with 2, 3 and 4-wire zone valves, unlimited zone expansion
  • CSA approved
  • Pump exercising, post purge
  • Four ground screws, Top, bottom and back conduit knockouts
  • LED for each zone, priority, end switch and RoomResponse, away signal shared between tekmar thermostats
  • Two spare fuses included
  • Zone priority, priority override


  • Agency Approvals: CSA C US
  • Ambient Conditions: Indoor use only, 32 to 122 degrees F (0 to 50 degrees C), RH less than or equal to 90 percent non-condensing
  • Control Load: 7 VA
  • Control Type: Microprocessor control, this is not a safety (limit) control
  • Dimensions: 8-3/16" H x 10-11/16" W x 2-3/8" D (208 x 271 x 60 mm)
  • Enclosure Material: Cover: ABS plastic, Base: galvanized steel
  • Enclosure NEMA Rating: NEMA 1
  • End Switch Relay: Boiler, DHW 24 V (ac), 5 A
  • Fuses: T5A 250 V slow blow, two spare fuses included
  • Mod Boiler Output1: 0-10 V (dc) 500 ohms min load impedance
  • Mod Boiler Output2: 4-20 mA 1 k ohms max load impedance
  • Power Supply: 115 V (ac) plus / minus 10 percent, 60 Hz, 11 A
  • Pump Relay: 230 V (ac), 5 A, 1/3 hp
  • Transformer: 24 V (ac), 40 VA, expandable to 80 VA with additional transformer M3069 (sold separately)
  • Zone Valve End Switch: 24 V (ac)
  • Zone Valve Outputs: 24 V (ac), 2 A max per output
  • Zoning - Thermostat Type: Zone Valve Control