HVAC in Detroit means a long heat season in an older house, then heavy summer air off the river. Some blocks still run boilers and radiators. Others have a furnace jammed in the basement beside the water heater. Upper floors may still rely on a window unit. If there is no heat tonight, say that before you describe the brand. If only one room fails, say where that room sits.
A cold room is not always a dead boiler. Heat leaks through a bare attic hatch and a fireplace that will not seal. A choked filter or a collapsed duct can imitate a dead compressor in July. Ask what was ruled out before a major part is condemned. Salt and snow pack the outdoor unit in a narrow side yard until it cannot breathe.
Replacement should follow the house, not the label on the old cabinet. Radiator houses and ducted houses are not the same plan. Hanging new outdoor equipment on an old basement coil will not behave like a matched pair in a plaster house with weak ducts. Ducts through a damp basement or a hot attic need a look before they are reused untouched. Say if the heat is steam, hot water, or forced air.
Summer is real here even though winter has the reputation. Heavy upstairs air, an iced coil, and a flat condensate line show up on the first sticky week. A window unit dripping into plaster is a wall problem too. Do not delay a no-heat call to hunt a model plate in the dark. Combustion equipment still needs a clear flue.
Say heat or cooling, boiler or furnace, and whether the outdoor unit is buried or merely old. Name the floor that fails. If a freeze loss may become a claim, say that too. Call the number on this page.