Key Takeaways
•The Direct Answer: No heating fuel wins in every Lexington home. Oil has no conversion bill on day one. Gas may be the cheapest fuel where it is available. Compared with oil, a heat pump saves the most in a well-sealed house with a reasonable electric rate.
•The Risk: Massachusetts heating oil is 77.88% higher than a year ago, according to Energy Information Administration (EIA) weekly data. An oil home's yearly cost can jump fast.
•The Help: Mass Save rebates reach $8,500 for a whole-home air-source heat pump, the top tier. Mass Save's 0% HEAT Loan can cover up to $25,000, so the upgrade can stay out of your mortgage.
•The Bottom Line: Before closing, get the seller's fuel bills and inspect the tank and electrical panel. Then run three quick math steps.
Why Doesn't "Updated Heating System" Tell You Enough?
Lexington listing sheets love the phrase "updated heating system." It sounds reassuring. It tells you nothing about what the home actually costs to heat.
Plenty of Lexington starter homes still run on oil. Others use gas. A growing number have switched to electric heat pumps. Each option can make sense — just not in every house.
Before closing, ask three questions: How much heat does the house need each year, measured in MMBtu (millions of heat units)? How much of the fuel actually becomes usable heat, based on the system's efficiency? And what does that fuel cost today?
What Does Staying on Oil Really Cost?
Oil's big advantage is simple: no conversion bill on day one. That matters when your cash is already stretched across the down payment, inspection, and moving costs.
The tradeoff is price risk. EIA weekly data puts Massachusetts heating oil at $6.119 per gallon statewide — 77.88% higher than a year earlier.
Heating Oil Price Shock: Current Level and Recent Changes
Headline Massachusetts heating oil level and the week-over-week and year-over-year changes; mixed units are presented as a snapshot rather than a chart.
Current Price
Current Level6.119
Prior Benchmarks
Value from Last Week5.742
Value from 1 Year Ago3.44
Change
Change from Last Week6.57%
Change from 1 Year Ago77.88%
To turn that statewide price into a yearly bill, you need a heating load. One reference point, pulled from a heating cost chart modeled on newer homes, is an 88.35 MMBtu annual load.
The next two figures are common rule-of-thumb assumptions — swap in your inspector's or installer's numbers when you have them. Each gallon of oil holds about 0.1385 MMBtu of heat, and an older furnace converts roughly 80% of it into usable warmth.
•Gallons per year = 88.35 ÷ (0.1385 MMBtu per gallon × 0.80 furnace efficiency)
•That equals about 797 gallons per year
•At that $6.119 price, the annual cost lands around $4,877
Because the load figure comes from newer construction, older and draftier starter homes will likely burn more. A smaller or well-insulated home may need less.
Your best number is the seller's actual oil delivery history. Ask for 12–24 months of records before waiving your inspection or financing protections.
Then there's the tank. MassDEP figures put a clean underground removal (no leak) at $800 to $3,500. And 30 to 40% of underground residential tanks show some soil contamination, which stacks cleanup costs on top of removal.
Massachusetts Underground Oil Tank Risk and Removal Costs
Snapshot of reported underground oil tank removal costs and contamination risk in Massachusetts.
Removal Cost
Typical removal cost (clean removal) - low end$800
Typical removal cost (clean removal) - high end$3,500
Contamination Risk
Share of underground residential oil tanks that show some level of soil contamination30 to 40%
Program Rule
Tanks eligible for narrow state cleanup fund must be registered beforeOctober 1988
Source:Massachusetts Department of Environmental Protection (MassDEP) (as reported)
Inspection rules in offers can shift, so confirm current practice with your agent — but hold onto your inspection contingency. Ask about the tank's age and location, burner condition, service records, and any signs of leakage.
When Does a Heat Pump Pay Off, and When Doesn't It?
The Town of Lexington says today's cold-climate heat pumps can hit 400% efficiency — up to 4 units of heat for every unit of electricity, since the system moves heat rather than burns fuel. Many models still heat efficiently down to -15°F. You also get air conditioning, something plenty of older Lexington homes lack.
But the house has to be ready. A drafty home makes the heat pump work harder, and a high electric rate shrinks the math in its favor.
Starting from the same 88.35 MMBtu load, and assuming the heat pump delivers about 2.5 units of heat per unit of electricity on a typical winter day, the math runs like this:
•kWh per year = 88,350,000 ÷ (3,412 × 2.5)
•That equals about 10,358 kWh
•Multiply that by the electric rate on your Eversource or Lexington Community Choice bill
A few cents per kWh changes the outcome entirely. So compare this house, this insulation level, and this electric rate — not "oil vs. heat pump" as a general rule.
Rebates ease the upfront hit. Per HeatPumpTab's summary of 2026 Mass Save rules, whole-home rebates hit the $8,500 cap at 4 and 5 tons (a measure of heating and cooling capacity, not weight — bigger homes need more). Partial-home and basic tiers pay far less.
2026 Mass Save Heat Pump Rebates by System Size and Tier
Dollar rebate amounts for typical heat pump system sizes under Whole-Home, Partial-Home, and Basic tiers.
Whole-Home
Partial-Home (before bonuses)
Basic
| Series | Label | Value |
|---|---|---|
| Whole-Home | 2 tons | $5,300 |
| Partial-Home (before bonuses) | 2 tons | $2,250 |
| Basic | 2 tons | $500 |
| Whole-Home | 3 tons | $7,950 |
| Partial-Home (before bonuses) | 3 tons | $3,375 |
| Basic | 3 tons | $750 |
| Whole-Home | 4 tons | $8,500 (cap) |
| Partial-Home (before bonuses) | 4 tons | $4,500 |
| Basic | 4 tons | $1,000 |
| Whole-Home | 5 tons | $8,500 (cap) |
| Partial-Home (before bonuses) | 5 tons | $5,625 |
| Basic | 5 tons | $1,250 |
Source:HeatPumpTab
Many drafty starter homes land in those lower tiers at first. If air sealing and insulation push you into whole-home qualification, the rebate difference can be worth thousands.
Don't assume every incentive still applies. The town page still lists federal tax credits, but HeatPumpTab notes they don't apply to heat pumps installed in 2026. Confirm current Mass Save amounts before you budget them in.
What Are the Key Differences at a Glance?
Here's how the three options compare on upfront cost, price risk, and how much a well-sealed house matters.
Key Differences at a Glance
Compares oil, gas, and heat pump heating options for Lexington homes by upfront cost, price risk, weatherization need, and air-conditioning benefit.
| Category | Oil | Gas | Heat Pump |
|---|---|---|---|
| Day-one cost | None if working | Conversion plus gas line | Install, minus rebates |
| Price risk | High | Moderate | Tied to electric rate |
| Needs a tight house? | Helps | Helps | Essential |
| Adds A/C? | No | No | Yes |
Source: EIA (Massachusetts heating oil weekly); Angi 2026 conversion cost estimate; HeatPumpTab summary of Mass Save; Town of Lexington.
Oil costs least upfront but carries the biggest recent price swing. A heat pump's performance depends most on how tight the house is.
For many first-time buyers, the practical move may be "dual fuel" — a heat pump paired with a backup furnace. You run electric heat most of the time, with a familiar backup for extreme cold or high-rate stretches. It also means you're not ripping out the existing system right after closing.
What Are the Common Objections to a Heat Pump?
"Massachusetts electricity is expensive."
Take $0.36/kWh as an example rate, then check your own bill. At that rate, the 10,358 kWh estimate for this heating load runs about $3,729 a year — against roughly $4,877 for oil on the same load.
So even at a high electric rate, the heat pump wins in this example. Oil would only come out ahead if electricity climbed above roughly $0.47/kWh, or oil prices dropped. That conclusion assumes a house as tight as the newer-home estimate and a heat pump hitting 2.5 efficiency. In a drafty house, or with a worse rate, that gap narrows fast.
Keep in mind a winter electric bill also covers lights and appliances, not just heat — don't mistake the total for the heating cost alone. And be skeptical of anyone promising a specific savings number. Every house performs differently; compare using the listing's actual bills and current rates.
"Why not just convert to gas?"
Gas may well be the cheapest fuel per unit of heat where it's available. But Angi's national 2026 estimate puts an oil-to-gas conversion at $3,800 to $13,000, and a gas furnace gives you no air conditioning. Gas service and connection costs vary by street, so check the specific address with National Grid.
What Should You Budget Before You Sign?
Start with the house, not the fuel.
If the house is leaky: keep oil for now, weatherize first, and budget from the seller's real oil records.
If the house is tight and your electric rate is competitive: a heat pump may be the better long-term move.
Mass Save's 0% HEAT Loan covers up to $25,000 and funds 75–100% of recommended weatherization costs. The town lists Eastern Bank, Lexington Municipal Federal Credit Union, and Hanscom Federal Credit Union as HEAT Loan lenders.
Before closing, work through this checklist:
•Request 12–24 months of oil, gas, and electric bills from the seller.
•Ask the inspector about the oil tank, burner, and service history.
•Confirm the electrical panel's amp capacity — a heat pump may require an upgrade.
•Ask whether the home has had insulation or air sealing work.
•Check whether gas is available on that specific street.
•Use Lexington HeatSmart: weatherize, meet an Energy Advisor, collect at least three vetted quotes, upgrade electrical if needed, then install.
Purchase price, assessed value, and school assignment tend to get all the attention. But your heating bill shows up every winter you own the home.
Want help with a specific property? Send the listing, fuel type, and any seller utility records. We can walk through the budget together.
