Oil vs Propane vs Heat Pump in Chester County
The cheapest fuel is the one that turns the most of your dollar into heat in your house.
Unionville homes heat with almost every fuel there is: oil boilers in farmhouses, propane past the gas lines, PECO gas closer to town, and heat pumps in newer builds. This guide compares them on heat content, efficiency, cost per million BTU, safety, upkeep and lifespan, and shows which fits which kind of house.
- Free referral service, not a contractor
- Independent local HVAC companies
- No obligation
What are the home heating options in Chester County?
Chester County homes heat mainly with heating oil, propane, natural gas where PECO gas lines run, air-source heat pumps, dual fuel systems that pair a heat pump with a furnace, geothermal heat pumps, and electric resistance heat. Which ones are open to you depends mostly on whether a gas main reaches your road.
Around Unionville, many roads in East Marlborough, West Marlborough and Newlin are past the gas main. That leaves a real choice between oil, propane and electric options. Closer to Kennett Square, Longwood and West Chester, natural gas is often on the table too.
Two words matter in every comparison. Fuel is what you buy: gallons, therms or kilowatt-hours. Equipment is what turns it into heat: a furnace, a boiler or a heat pump. A good fuel in a poor system can still cost more than a pricier fuel in an efficient one.
How does each heating system make heat?
Oil, propane and gas systems burn fuel in a furnace or boiler and vent the exhaust outside. Electric resistance turns electricity directly into heat. A heat pump uses electricity to move heat from outdoor air or the ground into the house, which is why it can deliver more heat than the energy it uses.
Heating oil
An oil burner sprays a fine mist through a nozzle and lights it inside a furnace or boiler. Oil is stored in a tank in the basement or outside and delivered by truck. It needs a chimney or a sealed vent.
Propane
Propane is stored as a liquid in a tank on the property and burned as a gas. A propane furnace or boiler works like a natural gas one, with propane-specific setup. High-efficiency models vent through PVC pipe.
Natural gas
Gas arrives by pipe from PECO, so there's no tank and no delivery schedule. Furnaces and boilers burn it the same way as propane. Availability ends where the gas main ends.
Air-source heat pump
An outdoor unit pulls heat from outside air, even in winter, and pumps it indoors. It also cools in summer. Ducted systems use an air handler; ductless mini splits use wall or ceiling heads.
Geothermal heat pump
Buried or drilled loops exchange heat with the ground, which the Department of Energy says stays around 40°F to 70°F a few feet down. Steadier source temperatures make it more efficient than air-source.
Electric resistance
Baseboard heaters, wall heaters or an electric furnace run current through elements. Every kilowatt-hour becomes heat at the point of use, but there's no multiplier like a heat pump has.
How much heat is in a gallon of oil, a gallon of propane and a kWh?
According to the U.S. Energy Information Administration, a gallon of heating oil contains about 138,500 BTU, a gallon of propane about 91,452 BTU, a kilowatt-hour of electricity 3,412 BTU, and natural gas about 1,036 BTU per cubic foot or 100,000 BTU per therm. Oil holds roughly half again as much heat per gallon as propane.
A BTU (British thermal unit) is the heat needed to warm one pound of water by one degree Fahrenheit. Heating bills are easiest to compare in millions of BTU, often written MMBtu.
| Fuel | Unit you buy | Heat per unit (EIA) | Units in 1 million BTU (before efficiency) |
|---|---|---|---|
| Heating oil | Gallon | 138,500 BTU | About 7.2 gallons |
| Propane | Gallon | 91,452 BTU | About 10.9 gallons |
| Natural gas | Therm | 100,000 BTU | 10 therms |
| Natural gas | Cubic foot | 1,036 BTU | About 965 cubic feet |
| Electricity | Kilowatt-hour | 3,412 BTU | About 293 kWh |
EIA notes it recalculates some conversion factors each year. The figures above are from its BTU explainer, checked October 2026.
What do AFUE, HSPF2 and COP mean?
AFUE is the share of fuel a furnace or boiler turns into heat over a season, so 95% AFUE wastes about 5%. HSPF2 is a heat pump's seasonal heat output in BTU per watt-hour of electricity. COP is heat out divided by energy in at one moment; electric resistance is 1.0, and a heat pump is usually higher.
You can roughly convert HSPF2 to an average seasonal COP by dividing by 3.412, because one watt-hour is 3.412 BTU. An HSPF2 of 7.8 works out to a seasonal average near 2.3: about 2.3 units of heat for each unit of electricity.
| Equipment | Rating used | Benchmark | Source |
|---|---|---|---|
| ENERGY STAR gas boiler | AFUE | 90% or higher | ENERGY STAR |
| ENERGY STAR oil boiler | AFUE | 87% or higher | ENERGY STAR |
| ENERGY STAR gas furnace (northern U.S.) | AFUE | Up to 18% more efficient than baseline models | ENERGY STAR |
| Modern oil burner | Steady state efficiency | 80% or higher with a flame retention burner; under 75% may be worth replacing | Energy.gov |
| ENERGY STAR split heat pump | HSPF2 / SEER2 | HSPF2 7.8 or higher, SEER2 15.2 or higher | ENERGY STAR |
| ENERGY STAR Cold Climate heat pump | HSPF2 and COP at 5°F | HSPF2 8.1 ducted or 8.5 ductless; COP at least 1.75 at 5°F; at least 70% of rated capacity at 5°F | ENERGY STAR |
| Electric resistance | COP | 1.0 (100% at point of use) | Energy.gov |
The Department of Energy says air-source heat pumps can cut electricity use for heating by up to 75% compared with electric resistance, and its electric resistance page puts typical savings near 50%. The gap reflects different equipment and climates, so treat both as ranges, not promises.
How do you compare heating costs per million BTU?
Divide the price per unit by the usable heat per unit. Cost per million BTU delivered equals price per unit divided by (BTU per unit × efficiency ÷ 1,000,000). Use your own fuel price and your system's AFUE or COP. The fuel with the lowest result costs the least to heat with.
- Oil. Price per gallon ÷ (0.1385 × AFUE). EIA's Pennsylvania residential heating oil average for the week of October 19, 2026 was $6.066 a gallon. At 85% efficiency: $6.066 ÷ (0.1385 × 0.85) = about $51.50 per million BTU.
- Propane. Price per gallon ÷ (0.0915 × AFUE). EIA's Pennsylvania residential propane average that same week was $3.163. In a 95% furnace: about $36.40 per million BTU. In an 80% furnace: about $43.20.
- Electricity. Price per kWh × 293 ÷ COP. Plug in the all-in rate from your PECO bill, supply plus delivery. At a COP of 1 (baseboard), each 10 cents per kWh costs about $29 per million BTU. At a COP of 2.5, the same rate costs about $11.70.
- Natural gas. Price per therm ÷ (0.1 × AFUE). Use the total per-therm cost from your PECO gas bill, not just the supply line.
EIA's weekly prices are state averages that exclude taxes. Your supplier's price may be higher or lower, and prices move through the season. Run the math with your own delivery slips and bills.
Break-even electric rates, using those October 2026 prices
| Heat pump COP at the moment | Matches 85% oil at $6.066/gal when power costs | Matches 95% propane at $3.163/gal when power costs |
|---|---|---|
| 1.0 (resistance strips only) | About 17.6¢/kWh | About 12.4¢/kWh |
| 1.75 (ENERGY STAR Cold Climate floor at 5°F) | About 30.8¢/kWh | About 21.7¢/kWh |
| 2.0 | About 35.2¢/kWh | About 24.8¢/kWh |
| 3.0 (mild weather) | About 52.7¢/kWh | About 37.3¢/kWh |
If your all-in electric rate is below the number in a row, the heat pump costs less than that fuel at that COP. These are calculations from EIA's statewide average prices, not local quotes.
Oil, propane, gas and heat pumps compared
Oil and propane need on-site tanks and deliveries; gas and electricity arrive by wire or pipe. Combustion systems need venting and carry carbon monoxide risk; heat pumps don't burn anything indoors. Boilers tend to outlast furnaces, and heat pumps have the shortest typical life of the group.
| System | Fuel storage and delivery | Venting and CO | Yearly upkeep | Typical life |
|---|---|---|---|---|
| Oil furnace or boiler | Basement or outdoor tank; truck delivery | Chimney or sealed vent; CO and soot risk if poorly tuned | Nozzle, filter, combustion and draft test every year | Furnace 15 to 25 yrs; boiler around 40 (InterNACHI) |
| Propane furnace or boiler | Leased or owned tank outside; truck delivery | PVC on high efficiency, chimney on older units; CO risk | Burner, safety controls, leak check, regulator | Furnace 15 to 25 yrs (InterNACHI) |
| Natural gas furnace or boiler | None; PECO pipeline | Same as propane; CO risk | Burner, flame sensor, ignitor, venting | Furnace 15 to 25 yrs (InterNACHI) |
| Air-source heat pump | None; electric service | No combustion indoors, no CO from the unit | Filters, coil cleaning, clear snow from outdoor unit | 10 to 15 yrs (InterNACHI) |
| Geothermal heat pump | None; ground loop on the lot | No combustion indoors | Filters, loop pressure and fluid checks | Indoor parts up to about 24 yrs; loop 50+ (Energy.gov) |
| Electric resistance | None; electric service | No combustion | Very little | Electric radiant heater about 40 yrs (InterNACHI) |
Lifespans are general guidelines with normal maintenance, not guarantees. A badly installed system of any type can fail early.
Which heating system suits which Unionville house?
Stone farmhouses with radiators usually keep a boiler and add ductless heat pumps. Colonials with ducts and central air are strong dual fuel candidates. New builds suit cold-climate heat pumps or geothermal. Converted barns often do best with mini splits or radiant floors. Gas access changes the math for any of them.
| House type | Common today | Options worth pricing | Watch for |
|---|---|---|---|
| 1700s to 1800s stone farmhouse | Oil boiler with radiators | Keep or replace the boiler; add ductless mini splits for shoulder seasons and cooling | Chimney liner, oil tank age, few duct chases |
| Village home in the historic district | Oil or gas boiler, some added forced air | High-efficiency boiler; mini splits placed out of street view | Masonry chimneys; ask the township HARB before exterior changes |
| 1970s to 1990s colonial | Oil, propane or gas furnace plus central AC | Dual fuel: heat pump on the existing ducts plus a furnace | Duct sizing, matching coil and refrigerant |
| Newer construction, 2000s on | Propane or gas furnace, heat pumps, attic air handlers | Cold-climate heat pump; geothermal if the lot allows | Electrical service size, multiple zones |
| Converted barn or carriage house | Propane, electric baseboard or nothing | Mini splits; radiant floor from a boiler or water heater | High ceilings, large volumes, stone walls |
| Addition or apartment over a garage | Electric baseboard | Ductless heat pump | Cost of resistance heat in a long winter |
For older masonry homes in particular, see heating an old stone farmhouse.
When does dual fuel make sense?
Dual fuel makes sense when a house already has ducts, needs a new air conditioner, and burns oil or propane. The heat pump carries the mild months cheaply, and the furnace takes over when it gets cold enough that burning fuel costs less or the heat pump can't keep up. The Department of Energy notes these systems are common in the Mid-Atlantic.
The handoff happens at a set outdoor temperature, often called the switchover or balance point. A good installer sets it from your fuel price and electric rate, using the same math as the break-even table above, not a factory default.
Dual fuel is a strong fit if
- The AC is near the end of its life anyway
- The furnace is newer and has a variable-speed blower
- You heat with oil or propane and want fewer deliveries
- You want a backup heat source in a long outage of one fuel
It may not pay off if
- You have PECO gas, a newer furnace and no AC plans
- The ducts are undersized for heat pump airflow
- The electric panel needs a costly upgrade first
Which heating fuel is safest?
Any system that burns oil, propane or gas can produce carbon monoxide if it's dirty, cracked or poorly vented, so it needs yearly service and CO alarms. Heat pumps and electric heat produce no combustion gases indoors. Every fuel is safe when it's installed correctly and maintained, and none is safe when it isn't.
- Oil: soot and puffbacks from delayed ignition; aging tanks that rust from the inside. Press the burner reset button once only.
- Propane: heavier than air, so leaks settle low. After a run-out, the system needs a leak check before it's relit.
- Natural gas: leaks smell like rotten eggs. Leave the house and call 911 from outside.
- Heat pumps: high-voltage equipment and refrigerant; keep the outdoor unit clear of snow and ice.
Any home with a combustion appliance, fireplace or attached garage should have CO alarms. See the carbon monoxide guide for placement and Pennsylvania's Act 121.
Are there rebates for switching fuels in 2026?
There's no federal 25C tax credit for heat pumps, furnaces or boilers placed in service after December 31, 2025. PECO electric customers may qualify for rebates of up to $300 on qualifying heat pumps and mini splits, applied for within 90 days. Confirm current amounts and rules on peco.com before you buy.
PECO also offers rebates to its natural gas customers, and it lowered gas rebate levels for applications on or after October 1, 2026. Oil and propane customers can still use PECO's electric rebates if they add a heat pump. Details are on the homepage rebates section.
Get connected with local companies and ask for a written quote on each system you're considering. The referral is free.
What to ask before switching heating fuels
Ask for a room-by-room load calculation, a written cost comparison using your own fuel and electric bills, the equipment's AFUE or HSPF2 and cold-weather capacity, and what happens to the old tank, chimney and venting. Ask too for the contractor's Pennsylvania HICPA registration number.
- Will you do a Manual J load calculation, not size from the old unit?
- What COP and capacity does this heat pump have at 5°F?
- At what outdoor temperature will a dual fuel system switch to the furnace, and why?
- Does my electrical panel have room, or does it need an upgrade?
- What happens to the oil tank and the old chimney flue?
- Who services this system in January, and how fast can you get parts?
More on contractor rules in Pennsylvania rules, and on replacing a furnace in furnace replacement. If you're keeping oil, see oil furnace repair; for propane, propane furnace repair.
Heating fuel questions from Chester County homeowners
Is oil or propane cheaper to heat with in Pennsylvania?
Using EIA's Pennsylvania averages for the week of October 19, 2026, propane in a 95% furnace came to about $36 per million BTU and oil at 85% about $52. Prices change weekly and vary by supplier, so run the formula with your own prices.
Why does oil have more BTUs per gallon than propane?
Heating oil is a denser fuel. The EIA lists about 138,500 BTU per gallon for heating oil and about 91,452 for propane. That's why a fair comparison uses cost per million BTU, not cost per gallon.
Do heat pumps work in Unionville winters?
Yes. West Chester's January average low is about 22°F. ENERGY STAR Cold Climate heat pumps are tested to keep at least 70% of their capacity at 5°F. Many owners still keep a furnace or boiler for the coldest nights.
Can I add a heat pump and keep my oil boiler?
Often, yes. Ductless mini splits can heat and cool main rooms in fall and spring while the boiler covers the deep cold. The Department of Energy says mini splits are the most common choice for radiator-heated homes in the Mid-Atlantic.
Is geothermal worth it in Chester County?
It can be on larger lots or new builds. The Department of Energy says installation can cost several times as much as air-source, with energy savings that may recover the difference in about 5 to 10 years. The ground loop can last 50 years or more.
Should I switch from oil to natural gas?
Only if PECO gas reaches your road. Ask PECO about the cost of a service line, then compare the full job, including a new furnace or boiler and venting, against a heat pump or dual fuel option.
Is electric baseboard heat expensive?
It turns all its electricity into heat, but it has a COP of 1. The Department of Energy says a heat pump can cut that electricity use by about half or more. For additions with baseboard, a ductless heat pump is worth pricing.
Is this site a heating contractor?
No. UnionvillePAFurnaceRepair is a free referral service that connects you with independent local HVAC companies. Those companies set their own prices and terms. This site doesn't install or guarantee any work and may be paid for referrals.
Sources
- U.S. EIA: British thermal units and fuel conversion factors.
- U.S. EIA: Heating Oil and Propane Update, Pennsylvania residential prices for the week of October 19, 2026.
- U.S. EIA: weekly residential propane prices and weekly residential heating oil prices.
- Energy.gov: Heat pump systems.
- Energy.gov: Geothermal heat pumps.
- Energy.gov: Electric resistance heating.
- Energy.gov: Oil-fired boilers and furnaces.
- ENERGY STAR: Air-source heat pump key product criteria.
- ENERGY STAR: Furnaces and ENERGY STAR: Boilers.
- InterNACHI: Standard estimated life expectancy chart for homes.
- PECO rebate terms and the end of the federal 25C credit, as summarized on the Unionville furnace guide.
Written by Lawrence. Updated October 25, 2026. Facts on this page were checked against the public sources listed above.
This is general information from a free referral service, not a heating contractor. For gas smells or carbon monoxide alarms, leave the house and call 911.
Related furnace help
Weighing a fuel switch? Get connected with local heating companies.
Have a year of oil or propane delivery slips and your electric bills handy. They let an installer compare options with your real usage, not guesses.
One call to (724) 241-4851 connects you with independent local HVAC companies that serve Unionville and nearby Chester County communities. It's free, with no obligation.
Have this ready when you call
- Your town or road
- Your fuel: oil, propane, gas or electric
- What the system is doing, and any blinking light code
- Whether you smell gas or oil (if so, leave and call 911 first)
Free referral service. Not a heating contractor. Companies are independent and set their own prices.