There are no tank heaters on the Isata 5. We use a duct run off the furnace to heat the tanks...including the valves. The pass through cavity where all the tanks and utilities are have at least one (but I think we ended up with 2) holes in the ceiling of that area where you will find a furnace outlet. Not sure why it would have switches for tank heater??? picture? maybe it was just part of the standard multiplex software.
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