HVAC in Massachusetts is still, in a great many houses, an oil or gas boiler and a loop of pipe, not a full duct system. Steam knocks in Worcester triple-deckers. Hot-water baseboard lines the walls of ranches farther out. The Cape may need cooling more than the Berkshires, but both need heat that survives a power cut and a cold week. Say what you have in the cellar before you name a brand you saw on a truck.
A boiler that short-cycles, a radiator that stays cold at the far end, and a chimney that was lined for a different appliance are three separate problems. Oil tanks in basements leak into the soil under the floor if they fail quietly. Buried tanks in older yards are their own worry when you smell oil near the foundation. Note the smell, the soot, and whether the heat dies on the coldest mornings or runs without stopping.
Ductless heads get added to houses that never had ducts, especially sunrooms and finished attics. They do not fix a steam system that is full of air, and they do not dry a damp coastal cellar by themselves. Filters, condensate lines, and outdoor units near salt air need a plan, or the new equipment quits while the old boiler is still the real heat. Tell the caller if any room was added after the original system.
Humid summers on the eastern side of the state load houses with moisture even when the temperature is only warm. A finished basement that smells sweet after July needs dehumidification as much as it needs a vent. Inland nights drop harder, and heat pumps that were sized for a mild week struggle when the Berkshires go deep cold. Ask what the backup heat is, and whether the house can live on it.
Have the fuel, the age of the boiler or furnace if you know it, and the room that fails first. Say whether this is no heat, a leak at a valve, a smell, or a plan to cool a house that has never had it. Mention a recent power loss if the system needed a reset. Call the number on this page.