HVAC in Wilmington has to cool brick that holds a humid afternoon off the rivers, then heat houses on hills that take a real winter wind. Radiators still serve many older homes. Ducts show up in later houses and in reworked rows, often jammed into closets. A top floor under a roof can cook while a basement cut into the hillside stays clammy. Say which of those is your house.
Outdoor units on tight side yards, or against a rock bank on a hill lot, lose the airflow they need. Shade from old trees helps the walls and hurts a condenser that never dries out. Inside, a boiler in a basement may be older than the thermostat on the wall. If you have radiators plus a window unit, say so instead of pretending there is one system. The fall line does not care which equipment was fashionable.
Describe the bad floor. The top of a tall brick house will not cool. A room on the windward hill will not heat. Ice on the outdoor line, a smell at the first cold night, and a filter you cannot reach are useful facts. Brick gives heat back after sunset. A house above the Brandywine can feel that on the west wall while the river side of town feels the damp first.
Say the fuel if you know it, and say whether the equipment sits in a rock basement, a closet, or outdoors with poor clearance. A tune-up before summer and a no-heat morning are different calls. Do not name the failed part unless you truly know it. Party walls in the lower streets pass sound. They are not a heating plan.
Spend the call on symptoms and on hill versus river flat. HVAC in Wilmington is humid air off the Christina and the Delaware, cold on the Piedmont edge, and equipment stuffed into older brick. Call the number on this page.