ACA Appliance & Air Conditioning, LLC provides work on a selection of household appliances. As we attempt to offer web site experiences for browsers that support new web standards and safety practices. Set your thermostat to AC mode and decrease the temperature setting. If the furnace fan kicks in, the problem isn’t in the furnace. If the fan doesn’t run, try resetting the furnace circuit breaker. If the fan still won’t start, call a professional — the fixes shown right here won’t work.