HVAC in Oregon is a mild wet winter on the west side and a colder season east of the Cascades, plus a cooling problem many houses never had until a heat wave. Furnaces, wall heaters, and heat pumps are not interchangeable. Say the town and whether the call is heat that quit, rooms that cooked, or ducts that sweat in a crawl.
Combustion air, the flue, and the exchanger come before comfort talk. If you smell trouble, stop the unit. Crawl ducts on the wet side sag, sweat, and dump air into a space that is already damp. That is a different visit from a burner that will not light or a heat pump that quit on the one hot stretch. Ask what was ruled out.
A brochure size is a guess in a climate that spends months cool and then turns sharp. Ask whether the load was figured for this glass, this shade, and this lack of original cooling, or copied from the old label. Matched equipment matters if a heat pump is being asked to do a job the house never ducted for. Labels compare a test. They are not a promise about your fuel, and a window unit in one room is not a whole-house plan.
Replacement is saner outside a heat wave and outside the wettest stretch, and a dead system does not offer that choice. Say if the house is uncomfortable now. Bedrooms under a low roof and rooms over a cold crawl expose a lazy duct layout the first time the weather stops being mild. A thermostat in a sunny front room will lie about the back of the house. Mention that pattern if it is yours.
Say heat or cooling, the town, and whether the unit is dead or only losing. Mention sweating ducts, a flue issue, or a house that was built with almost no cooling. If the upstairs cooked or the heat will not catch, say so first. The next heat wave will not care that the winter felt easy. Call the number on this page.