Showed up for an evaluation on a gas furnace system coils have been freezing and thawing back out resulting in excess amounts of water flooding the emergency pan causing it to overflow after diagnosing the system I found the problem to be the zoning board and the bypass damper homeowner has chosen to eliminate the zoning system all together therebye leaving the downstairs thermostat in full control I verified that the two zoning dampers for upstairs and downstairs are both power closed and spring open and verified that they are in the open position with no power applied to them verified systems functionality before leaving left it in cool mode