Furnace Installation in Wilmington, DE
A new furnace here will run from October through April every year. Tell us about the house, and a licensed contractor who covers New Castle County will get in touch.
Tell us about the job
It takes about a minute.
Seven months of heat, out of a furnace that has to hold up
Your furnace runs from October through April here, seven months a year. Winter nights average 27°F, so it is not just cold snaps, it is a long stretch of steady work. Whatever you install needs to carry that load without strain.
More than half the homes in the area heat with gas, and any non-weatherized gas furnace built since November 2015 has to reach at least 80 percent AFUE. That is the floor, not a selling point. New Castle County also sees its share of winter storms and wind, and about 12 percent of Delaware households lost power for a day or more in 2024. If your furnace runs on electricity to light or run its blower, ask how it starts back up once the power does.
- 7 months
- October through April, your furnace is on duty
- 27°F
- the average winter night it heats against
- 54%
- of homes here heat with gas, so most furnaces here burn gas
- 80% AFUE
- the federal minimum any new unit must meet
NOAA nClimDiv, 1991–2020 normals
A high-efficiency gas furnace would save about $100 a year to run in New Castle County compared with a gas furnace.
Estimates for a typical New Castle County home, from EIA household energy data, Delaware fuel prices and NOAA climate normals. Your home will differ.
Delaware requires HVAC contractors to hold a state license.
Delaware tests and licenses the contractor, not the job itself. The license on file with the Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners tells you this contractor passed the state's exam and is on record with them. It does not mean a state inspector is coming to look at your furnace.
For a furnace installation, that inspection usually comes from somewhere else. Most cities and counties require a permit before a furnace is replaced and an inspection once it is in, and that is where the work in your house actually gets checked. Gas is the part worth the attention here. Just over half the homes in New Castle County heat with it, and a bad connection at the furnace is what a permit inspection is there to catch.
Sources: Delaware Code Online · Delaware Division of Professional Regulation
- What size furnace does my house need?
- It depends on your square footage, your insulation, your ceiling height, and how much window area faces outside. A furnace that's too big will short cycle, turning on and off before it heats the house evenly. One that's too small will run constantly and still leave the house cold on the coldest nights, and here that means nights averaging 27°F from December through February. A contractor works this out with a load calculation, not a chart based on square footage alone, since two houses the same size can need different sized furnaces.
- How do I know it's time to replace my furnace?
- Watch for uneven heat between rooms, a furnace that runs longer than it used to, or repairs that keep coming back. Rising gas bills with no other explanation are another sign, since a furnace losing efficiency burns more fuel for the same heat. Age matters too. Homes here need heat from October through April, seven months of the year, so a furnace nearing the end of its life is working hard most of the year, not just a few cold weeks.
- Is a high-efficiency furnace worth it?
- It depends on how long you plan to stay in the house and what furnace you have now. Any non-weatherized gas furnace made since November 2015 has to reach at least 80 percent AFUE, so even a standard model today wastes less fuel than older units did. A high-efficiency furnace burns less gas still, and that adds up over a heating season that runs seven months here. A contractor can tell you what the difference actually looks like for your house, weighed against your current furnace.