303V Tekmar Three Zone Valve Control with Priority

The Zone Valve Control 303V connects up to three thermostats and operates zone valves to provide heating to a zoned hydronic heating system. The 303V 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 and 3. The 303V 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 303V provides a RoomResponse signal to modulating-condensing boilers to optimize comfort while improving boiler efficiency.

Install Instructions
Specification Sheet

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