HVAC in Columbus has to finish an inland winter and a humid summer with only a short gap. Snow melts off the outdoor unit and then refreezes around it. It does not sit in a lake drift for weeks, and it still blocks the fan. Older basements hold furnaces beside water heaters, with thin ducts to the upstairs. Newer houses park ducts in attics that bake. Say no-heat or no-cooling before the brand.
A choked filter, a collapsed basement return, and a closed bedroom vent imitate a dead compressor. Heavy upstairs air while the thermostat looks satisfied is the first humid week of summer, and it is airflow or a coil until shown otherwise. Ask what was ruled out. A flue that nobody has looked at is not a thermostat story. Radiators still exist on some older streets and they are not a duct job.
Size the new equipment for a house that thaws in January and bakes in July, not for the label on the old cabinet. Outer subdivisions hide ducts in those attics. Older brick streets often still have a basement furnace, and hanging a new outdoor unit on the old coil will not behave. Waiting on a mild week is how the call lands on the worst night. Say if radiators are still in the picture. The cellar has to give combustion equipment air.
Clogged condensate lines stain ceilings and get mistaken for roof leaks. Window units upstairs drip into plaster and become a wall repair. Clear ice from the outdoor unit only when you can do it safely. Do not open gas parts. If a freeze on an outside wall may turn into a claim, say that when you describe the equipment. Salt and slush from the street reach side-yard units even in an inland city.
Say basement ducts or attic ducts, and which floor fails. One cold room over a garage is not a whole-system death. Have the model plate only if it is in reach. Call the number on this page.