HVAC in Utah is a furnace state on the Wasatch and in the mountains, and a cooling state in Washington County. Inversion winters along the Front mean the heater runs while the valley air sits cold and dirty, filters load, and a weak furnace is not a minor comfort issue. Boilers and radiators still heat older brick houses. Forced air is everywhere else. Cooling is common now and still secondary to heat, except in St. George, where the condenser carries a long season and the attic or the garage is hot. Evaporative coolers remain on some older dry houses and are not the same machine.
Say heat or cooling first, and say the town. No heat: does the furnace or boiler try to start. Ask whether the heat exchanger, the flue, and combustion air were part of the look. A canyon wind can disturb venting. A replacement copied from the old label may be wrong for the house, especially if ducts are leaking or the system is a boiler with radiators that someone is trying to abandon. Ask if the new equipment is matched and sized for the house. Ask about filters if the complaint is stale air all winter. That can be a filter and a house that never opens, not a dead blower.
No cooling in the south is closer to a desert call. Say whether the outdoor unit is silent or running and useless. Ask what gets ruled out before a compressor is blamed. Condensate clogs and cooler curbs both stain ceilings. In the north, a frozen condensate line in winter is its own cold-climate failure. Mention it if the attic air handler has ever iced.
Service heat before the first real storm and cooling before the southern hot stretch. If the house is unsafe to occupy now, skip the season plan. Call the number on this page.