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Taco ZVC406 with mix of N/C and N/O Zone Valves
I want to have a Taco ZVC406 Zone Valve Control Module cycle my coal boilers circulator only when one or more of the zone valves on my system are open. Unlike most boilers a coal boiler must make heat continuously, whether the
home needs it or not, otherwise the fire goes out. Therefore it needs a temperature reducing "dump zone". My concern is that my aquastat linked high temperature "dump zone" valve is of the normally open type, whereas all of the homes regular thermostat linked zone valves are of the conventional normally closed type. The dump zones zone valve is continuously energized to force it closed, and it only opens when my high level boiler set point temp of 210 deg. F. is reached, at which time it opens and dumps the boilers excess heat.
Here is the crux of my problem: Since the single normally open zone valve is continuously energized under normal conditions, yet it is closed while energized, and the Taco ZVC406 runs the circulator whenever it senses one or more energized zone valves, will my circulator be running continuously (and worse yet, shut off right when it is actually needed the most if the dump zone valve opens due to excessive boiler temp while all of the other zone valves are closed), or will I be able to somehow wire the ZVC406 to cycle the circulator only when one or more of the N/C zone valves are energized and open, and/or when my N/O dump zone valve is de-energized and therefore open?