Re: Oil furnace zone 3 help
In your second set of pictures the top picture is a manual mixing valve, no electric. The silver box is a Honeywell diverting zone valve, bottom picture is a Taco zone control valve. Your control board is a Taco, I don't see any other wires other than zone 3 that would be used for DHW. On newer board versions the farthest right set of contacts (whatever number that may be) is dedicated to priority DHW. If desired it can be set up that if DHW is needed that far right valve will turn on and the others will auto turn off until the DHW is satisfied.
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