"Calvert’s mission is to serve your family and make your home comfortable, while wowing you with the experience and earning your trust as a customer for life."

 (302) 998-0460

  • $9 Diagnostic Fee and Safety Evaluation

    Included in the Diagnostic Fee:
    We will determine what is causing today's problem, then dig deeper and make sure no other problems are lurking around the corner.

    Included in the Safety Evaluation:
    We will visually inspect the furnace vent outside, and that there are no dangers associated with the natural gas or heating oil supply lines. We will also check the electrical power line and control wires for potential problems.

  • The Silver Club Membership

    Club members get our best pricing. Just one service call could easily save more than an entire years worth of membership dues.

    Only $14.95 a month!
    • • 0$- evaluation fee
    • • Same/next day service
    • • 20% off repairs, annual maintenance
    • • Good for both furnace and AC
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  • Here when you need us

    We provide fast, same-day service from technicians that were personally trained by the owners. They are skilled, polite and clean-cut. They are the kind of guys you would be proud to call 'son'.

    What makes us different is we know that mistakes can happen. We are prepared to step up, take ownership, and make things right—right away. We promise, you won't go wrong by choosing Calvert.

    ~ Chris & Dave, Owners
  • Oil Burner Replacement

    Dear Neighbor,As one of the owners of Calvert Heating & Cooling and a partner in Licoln Oil, I am seriously concerned about the rising price of home heating oil. The reason for this rise in price is the government’s effort to fix the economy by printing dollars. Commodities like oil and precious metals (like gold) always rise in cost as we devalue our dollar. The Fed has committed to printing 40 billion extra dollars a month until the economy turns the corner. Strange but true, natural gas and electricity will not be affected by the dollar’s decline. Because of new methods of developing natural gas, our nation is actually facing a glut of the product! The price of electricity will be tied to the price of natural gas, and prices look stable for the next 10 years, at the very least. Most homes in our area with oil burners burn 600-800 gallons of oil a year. Do the math…… that is $2400-$3200 a year just for oil and rising!
    Please consider the alternatives.

    Chris Lenhard

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Our Services

We install / Replace:

  • ductless mini splits
  • heaumps
  • geo-thermal
  • natural gas furnace
  • natural gas furnace
  • propane furnace
  • unit heaters
  • radiant floor systems
  • hydronic (boilers & radiators) systems
  • steam boilers
  • high velocity duct systems
  • central air conditioners
  • humidifiers and humidification systems
  • thermostats
  • zoning systems
Repairs on all brands:
Diamond 5 Star Dealer Geo-thermal Systems
Trane Comfort Specialists Trane Comfort Specialists
Trane comfort products Honeywell Humidifiers & Thermosats
Trane Comfort Specialists
York Certified Comfort Exert Arzel Zoning Products


Calvert Membership Club
Club members get our best pricing. Just one service call could easily save more than an entire years worth of membership dues. Learn more about our membership club here.

Call the company your neighbors trust

Diane P. -
Landenberg, PA

"Always so courteous and helpful! Very fair and honest."

Valerie S. -
Magnolia, DE

"Honest, punctual service with very knowledgeable associates."

Michael B. -
Newark, DE

"Returned my call promptly and was able to provide same-day service. "

Click to Read Testimonials from Your Neighborhood!

A Message From the Owner…


More than 50 percent of all heat pumps have problems with low airflow, leaky ducts, and incorrect refrigerant charge.

Read More

Air Conditioning

Paying attention to your air conditioning system saves you money and reduces environmental pollution.

Read More


Heating & Air Conditioning are things most people take for granted. We see it as our duty to ensure that they are working for you. Services FAQ »

Read More

Service Locations:

Elkton, MD
Rising Sun, MD
Millville, MD
Media, PA
Garnett Valley, PA
Kenennt Square, PA
Avondale, PA
Oxford, PA
West Chester, PA
Chadds Ford, PA
Avongrove, PA
Wilmington, DE
Claymont, DE
Newark, DE
Hockessin, DE
Middletown, DE
Townsend, DE
Smyrna, DE
Dover, DE
Delaware City, DE