HVAC in Salt Lake City is a furnace that has to be boringly reliable during inversion weeks, plus cooling that matters in July and is still not the main event. Cold air pools in the valley, the outside air is not a relief, and a heater that short-cycles or dies is the call. Boilers and radiators still serve older brick houses and should not be diagnosed as forced air. Evaporative coolers on some older homes are a third machine. Filters load when the valley sits dirty for days, and a packed filter can make a good furnace act weak. Canyon wind can disturb a flue. Say what the house is doing before anyone names a part.
No heat needs the first sentence. Does it try to start. Is there a smell. Is the thermostat calling and the basement unit silent. Ask whether the heat exchanger, the flue, and combustion air are in the look. Ask about the filter and the return before a blower is condemned. If the plan is replacement, ask whether the new equipment is sized for this house and whether the ducts or the radiators are part of the scope. Abandoning a boiler for forced air is a different project from swapping a furnace. Say which you are considering.
Cooling calls are real in the hot stretch. Say whether the outdoor unit runs. Condensate lines that freeze in winter and clog in summer both stain ceilings. A cooler curb leak is not a refrigerant leak. Mention the machine you actually have. Stale air all winter may be a filter, a closed house, and an inversion, not a failed system. Say how long the valley has been stuck so that possibility stays on the list.
If there is no heat while the inversion holds, do not wait for a nicer day. Call the number on this page.