A year of heating and cooling care in Dover
NOAA's engineering weather station at Dover Air Force Base sits right in town, so its numbers describe Dover's own weather: a 1% summer design temperature of 89°F and a 99% winter design temperature of 17°F. A system here earns its keep at both ends of the year. These seasonal checks keep it ready and catch small faults before they turn into an emergency call on the hottest or coldest night.
Spring: March to May
Get cooling ready before the first sticky week.
- Swap the air filter and write the date on its frame.
- Clear leaves, pine straw and grass clippings from the outdoor unit, and keep plantings two feet back.
- Run cooling on a mild afternoon to confirm it starts and the supply air feels cool.
- Pour a cup of water into the condensate drain pan, or check the drain line, to make sure it flows.
- Schedule a cooling tune-up if the system hasn't had one in the past year.
Summer: June to August
The Dover Air Force Base station counts about 612 hours a year with the wet-bulb temperature above 73°F and about 1,723 hours above 67°F, and its design-day wet-bulb is 75°F. Humidity is the summer problem.
- If the house feels damp while the thermostat reads fine, ask a technician whether the system is short-cycling or the fan is running too fast for good moisture removal.
- Leave the fan on "auto" rather than "on" unless a technician advises otherwise; a fan running nonstop can blow moisture from the coil back into the house.
- Keep vents and returns unblocked by furniture and rugs.
- Watch for ice on the copper lines or water around the indoor unit; both need service.
- After a summer thunderstorm, make sure the outdoor unit restarts normally.
Fall: September to November
Turn your attention to heat before the first frost.
- Change the filter again.
- Run the heat on a cool day. A brief dusty smell is normal; a burning or electrical smell isn't.
- For gas furnaces, book a heating check covering burners, flame sensor, heat exchanger, venting and a carbon monoxide test.
- Test carbon monoxide and smoke alarms and replace their batteries.
- Make sure the heat pump's outdoor unit sits level and clear of fallen leaves.
Winter: December to February
NOAA lists about 51 freeze-thaw cycles in an average year at the base, so cold comes and goes.
- Expect a heat pump to frost up and run defrost; a cloud of steam during defrost is normal, a unit locked in ice isn't.
- Keep snow and ice off the outdoor unit and away from any furnace intake and exhaust pipes on an outside wall.
- If backup heat seems to run constantly, have the heat pump checked.
- Hold the thermostat fairly steady on the coldest nights instead of making deep setbacks that call for backup heat in the morning.
When it's time to replace
Delaware is in the Department of Energy's hot-humid Southeast region. Split-system central air conditioners installed on or after January 1, 2023 must be rated at least 14.3 SEER2, and split-system heat pumps must meet 14.3 SEER2 and 7.5 HSPF2. If a big repair lands on an old system, ask for a replacement quote that includes a load calculation and a duct check, and compare running costs, not just prices.
Before you hire anyone, use the Delaware Department of Labor's lookup of registered construction contractors; Delaware law requires construction service businesses to register with its Office of Contractor Registration before beginning work.
Keep a record
Keep a page for filter changes, service visits and repairs, along with the model and serial numbers of the indoor and outdoor units. It speeds up warranty claims and gives the next technician the system's history.