The District's core heats overwhelmingly with Washington Gas, and this guide will be honest about that shortly. But ride the metro outward and the fuel map changes: oil tanks persist in the older Montgomery and Prince Georges stock that predates the gas mains or sits beyond them, the prewar colonials and capes around Kensington, Olney, Sandy Spring, and out toward Damascus and Poolesville, and electric baseboard hides in flats and conversions on both sides of the line. For those households the heating bill is the largest utility line of the year, and the 2026 arithmetic deserves a clean run, fuel by fuel.
The Oil Baseline
An oil-heated house of ordinary size in this climate burns 500 to 800 gallons a winter; the region's design nights settle into the upper teens, cold enough to work a burner steadily from December through February. At recent prices in the high $3 range per gallon, fuel alone runs $1,900 to $3,000. Add the annual service contract oil burners require, $200 to $400, and the true yearly cost sits near $2,100 to $3,400.
Then the costs without receipts: deliveries bought in lumps on a moving market, prebuy contracts gambled every summer, and a tank whose failure mode is an environmental remediation story with a four-figure floor.
The Heat Pump Side
A modern cold-climate heat pump moves heat rather than making it, delivering roughly two and a half to three units of heat per unit of electricity across a DC-area season, and the current equipment generation holds its capacity through upper-teens design nights with headroom to spare, per our equipment guide. Serving the same load, annual electricity typically runs $900 to $1,600 here.
| Annual cost | Oil system | Cold-climate heat pump |
|---|---|---|
| Fuel/electricity | $1,900 to $3,000 | $900 to $1,600 |
| Service contract | $200 to $400 | Minimal; filter cleanings |
| Cooling | Separate AC or window units | Included, same machine |
| Typical annual swing | $1,000 to $2,000 saved |
The cooling row carries extra weight in this metro. A DC July is a humidity problem as much as a temperature problem, and the same machine that retires the oil burner replaces the struggling AC and dries the house properly.
A Worked Montgomery County Example
A 1950s colonial near Kensington: 650 gallons at $3.60 is $2,340, plus a $300 service contract, call it $2,640 a year. A properly sized cold-climate system carries the same house for roughly $1,100 to $1,400 of electricity. The annual swing lands near $1,300, repeating every winter the house stands, and the summer bonus is central cooling that actually dehumidifies. Payback on fuel savings alone runs seven to ten years against a conversion priced in our installation cost guide, and any incentive claimed against the project compresses it from there.
The Honest Gas Paragraph
Now the majority case. The District's rowhouse core and most of the close-in Maryland suburbs heat with Washington Gas, and the gas math is genuinely close. Gas is cheap per unit of heat, and a sound furnace in a Petworth rowhouse or a Wheaton rancher is not a problem needing rescue.
For gas households the strong cases are specific and worth naming precisely: the air conditioner is at end of life, so one machine replaces two systems and the real comparison is heat pump versus furnace-plus-new-AC, which the heat pump frequently wins; the house has no ducts, where ductless heating-and-cooling beats window units on comfort alone; or a party-walled rowhouse's load is so small the whole project is cheap. What no honest bidder tells a gas household is that fuel savings by themselves repay the conversion the way they do for oil. They usually do not, and the vetting questions in our contractor guide exist for exactly that pitch.
Electric Baseboard: The Cleanest Math in the Metro
The stock that heats with resistance baseboard, older flats, English basements, condo conversions in Dupont Circle and Adams Morgan, some postwar infill, gets the shortest analysis. Baseboard delivers one unit of heat per unit of electricity; a heat pump delivers two and a half to three. The heating portion of the electric bill drops by more than half, with no fuel switch, no tank, and no combustion anywhere in the story. For these households the only real questions are sizing and head placement, and the payback is the fastest of any fuel case on this page.
The District Advantage, Where It Applies
DC addresses converting to a heat pump claim the DCSEU rebate, $250 to $5,000 tiered by equipment, plus $400 per circuit up to $2,000 for the electrical work conversions often require, with current terms through September 30, 2026. Maryland-side oil households, where most of this page's oil stock actually sits, claim their own utility's programs by address. Either way the discipline is identical: name the program in the first call, get the figure in writing on the quote, and price the project to stand on its operating math with the incentive as acceleration. The program mechanics live in our rebates guide.
The Summer Half of the Ledger
One line the oil math usually omits: what the house does in July. The oil stock in this metro mostly cools on window units or an aging separate AC, and both lose to the region's humidity. The conversion machine is the same machine in both seasons, and the summer dividend, real dehumidification and quiet central cooling, arrives free with the winter savings. Households comparing quotes should price the alternative honestly: keeping oil often means buying a new AC within a few years anyway, at which point the true comparison is oil-plus-new-AC against one heat pump, and the heat pump's case stops being close.
Volatility, the Cost Nobody Budgets
Oil's final cost is unpredictability. World events move the per-gallon price 30 percent between deliveries, and a cold snap can land an $800 invoice in the same month as the holidays. Electric rates move too, but through regulated filings, in steps a budget can see coming. Converted households report the same pattern every time: the savings were expected; the flat, predictable bill was the part they would not trade back.
The Tank, an Ending Worth Pricing
One more ledger line: the tank itself. Insurers ask about tank age at renewal, buried tanks complicate sales across Montgomery and Prince Georges counties, and a leak becomes remediation with a four-figure floor and a five-figure ceiling. Retiring the tank at conversion, pumped, cleaned, removed or properly decommissioned, typically runs a few hundred to a couple thousand dollars, converts an open-ended liability into a receipt, and belongs inside the project rather than waiting to become a buyer's leverage at sale.
The First Winter, Run Cautiously
Nothing about a conversion here requires a leap of faith. The cautious plan is standard: install in fall, keep the oil system as backup through the first winter, watch the heat pump carry the coldest nights on its compressor, then retire the tank in spring with a season of proof. The federal credit that once sweetened these projects ended December 31, 2025 and plays no part in the math above; the live programs are the local ones, claimed by address.
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