Plant ID# 9300-2880 NOTE 2: Resistor (1KΩ, 1⁄2 W) THERMOSTATS See Wiring Diagram: NOTE 2 may be needed between (24 VAC) Powered from Powered from Transformer A Transformer B W and C terminals.. Warning: When using Alternative Wiring diagram, wiring instructions must be followed so power originates from the boiler aquastat. Failure to follow these wiring instructions may result in a secondary source of power being connected to the boiler that may activate it under certain circumstances, causing injury or death.
Use copper wire only. 120 VAC wiring must have a minimum temperature rating of 75°C. Failure to follow this instruction can result in personal injury or death and/or property damage. 12-18 gauge wire recommended for 120 VAC connections, 14-22 gauge wire for thermo-stat connections, and 14-22 gauge wire for 24 VAC source connections.. View and Download Taco ZVC404-EXP-4 instruction sheet online. Zone Valve Control. ZVC404-EXP-4 control unit pdf manual download.