Durham, CT

Since 1984, Cromwell Energy, Inc. has been delivering quality HVAC installation, heating, and air conditioning repair services to the residents of Durham, Connecticut.

Home » Areas Served » Durham, CT

HVAC Services in Durham, CT

Since 1984 Cromwell Energy has been proudly providing residential heating and cooling services in Durham, Connecticut and the surrounding areas. Our licensed and insured technicians are experts in a wide variety of HVAC services. From air conditioning repair and installation, to furnace maintenance, repair and installation, Cromwell Energy is your local, go-to HVAC company. We also offer fast and affordable home heating oil delivery in Durham, CT, so you will never be left out in the cold.

No matter what type of HVAC service in CT you need, Cromwell Energy is here to help!

Heating System Installation, Maintenance & Repair

Proper maintenance is crucial for keeping your home boiler or furnace working efficiently. If you think your furnace is in need of maintenance, call the CT home heating experts at Cromwell Energy to professionally inspect and tune-up your system. If your furnace suddenly stops working, no need to worry! We offer 24/7 heating system repair CT so you can quickly enjoy the comforts of a heated home.

Thinking you need a new boiler or furnace installation in CT? We offer free estimates on all our installations, and financing options are available!

Air Conditioning Installation & Repair Services

Our HVAC repair technicians in Durham CT are experts in all type of AC systems, including central air conditioning systems and ductless mini-split units. No matter what type of HVAC service and repair you may need, we have the expertise to provide fast and cost-effective service. Cromwell Energy uses the top-rated brands on the market, including American Standard, Mitsubishi and LG.

From new air conditioning installation, to complete AC system repair, we take the time to properly diagnose the problem and outline your repair options. Don’t hesitate to give us a call 24/7 if you have an AC repair emergency as well. We are available day and night to make sure your HVAC system is running effectively, especially during those hot summer months.

Natural Gas Conversions

Cromwell Energy is one of Durham CT’s top choices for natural gas conversion. We will come out to your home and give you a thorough, free consultation for converting your home’s existing oil-burning system into a modern gas-burning configuration. There are many rebates and financing options currently offered in Connecticut to enhance the conversion from oil to natural gas. As a member of the CNG/SNG (UI) and Eversource contractor networks, Cromwell Energy has the experience and knowledge to convert your home to natural gas safely and affordably.

Home Heating Oil Delivery in Durham, CT

Cromwell Energy is one of the top companies offering heating oil delivery Durham CT. Our heating oil is treated with the HEATDOC additive to maximize efficiency, reduce sludge and inhibit corrosion. We have flexible delivery schedules, and provide many heating oil delivery options to suit your specific budget and needs.

From heating system installation, to oil delivery, to emergency HVAC repairs, our Durham, CT team is available to provide you with skilled, professional, and efficient service at an affordable price. Contact us today to learn more!

Oil Delivery & HVAC Services

In addition to our heating oil delivery, Cromwell Energy offers HVAC services throughout Middlesex and Hartford County, CT. We offer installation and maintenance services for most major brands of heating equipment (boilers, burners and furnaces) as well as commercial & residential central air conditioning (AC) systems. We also install the highly rated Mitsubishi ductless mini-splits and heat pump systems - which have become a go-to option for many Connecticut homeowners.

Heating Oil Delivery

To ensure that your home receives high quality fuel, Cromwell Energy delivers premium heating oil that contains the state-of-the-art HEATDOC additive package.

Learn More

Heating Services

We sell, install and maintain most major brands of heating equipment, (boilers, burners and furnaces) including Burnham, Buderus, Viessmann and American Standard.

Learn More

Air Conditioning Services

Cromwell Energy has the experience and expertise to professionally install and maintain your commercial or residential central air conditioning (AC) system.

Learn More

Customer Testimonials

At Cromwell Energy, customer satisfaction is always our highest priority. Read some of our many 5 star reviews!

Patrick Meaney

June 6, 2025

Great company for heating oil and HVAC needs. Staff provides excellent service and is very friendly and courteous. I have used them since 2018 and will continue to use them going forward. Can't recommend them enough!

Jen Tine

June 3, 2025

I have use Cromwell Energy for over 20 years and still couldn't be more pleased with the service I received for both my air-conditioning unit and boiler. The team was prompt, professional, and incredibly knowledgeable. They always take the time to explain what was needed to be done, answered all my questions with patience, and made sure everything was running smoothly before they left. Cromwell Energy clearly takes pride in their work and truly cares about their customers. The quality of service is top-notch-from the initial appointment to the final check. It's rare to find a company that's this reliable, respectful, and efficient. Highly recommend to anyone looking for trustworthy HVAC professionals.

Holly Linder

May 31, 2025

Great local company with excellent customer service. We have had Eric service our furnace the last few years and we have been very pleased with his professionalism and timeliness.

J T

May 30, 2025

My 30 year old boiler finally called it quits. I contacted a number of companies for estimates and I found Cromwell Energy to be the most responsive, flexible and willing to work with me. Today, their team of technicians remove the old and installed my new boiler. Once installed they took the time to go over the features. Technicians were neat and professional. Happy to be a new customer

James Henley

May 23, 2025

Great service as usual from Cromwell Energy. Technicians were on time and very effecient. Highly recommend!

Kelly Derosier

December 17, 2024

First time dealing with them. Annual service on a Navien Combi unit installed 2 years ago, they were great would highly recommend!

Joyce Walter

August 6, 2024

Cromwell Electric was wonderful to work with. Jeff gave a clear explanation of estimate for mini split a/c and installation happened within a few weeks (earlier than expected)! Tom, Jason and Ken were extremely professional and friendly. Got work done in a day without interrupting us in the home. Everything was cleaned up and took time showing us how to work the units and care for them. We will continue to use this company for multiple services when needed. A+++.

Lisa Raczka

August 2, 2024

Eric Mori came to do my annual service and he was exceptional! He took the time to answer all my questions, thorough and polite ! I was so pleased and he was neat and timely! He did both my AC and heating!

G - Pops

July 22, 2024

In the middle of a heat wave, our AC quit. Having used Cromwell Energy for furnace maintenance previously, I recalled the excellent service they provided. They did not disappoint again. Even though they were scheduling a week out, a technician became available the next day. Eric was professional, courteous, answered all my questions (and then some), and clearly was an expert in his field. Thanks to Eric and the excellent office staff, our AC stands ready for the next heat wave! Highly recommend Cromwell Energy!!

Nancy Joy

July 18, 2024

Cromwell Energy has always given us excellent service and we highly recommend them!

Barbara Hughes

July 15, 2024

I have used Cromwell Energy for more than 15 years. Eric performed the annual tune-up of my furnace and central A/C. He does a great job of explaining what is being done, was prompt, professional, and experienced. Highly recommend!