Hi...I live in a split ranch with 3 zoned hydro heat. When i call for heat in zone 1, same level the boiler is on, the boiler doesn't fire but circulates. When I can call for heat in zone 2 and 3, the boiler fires and circulates. Since zone 1 is knee wall type basement and boiler is close to living area, this has not created a problem temp wise. Do you think this is intentional, meaning a way to operate the ciculator w/o calling for heat.....and what would that purpose be? bleeding air or adding water???