What makes John Duffy the best in Commercial Services?

We are passionate about providing commercial services that will allow any business to function better—period.

John Duffy is family-owned and operated with a history spaning over four generations.

A people-first attitude and customer-driven approach defines our company values.

An authority in our field, we are devoted to providing high-quality energy solutions.

Wi-Fi Thermostat

Wi-Fi Nest Learning Thermostat

A $450.00 value!

with the purchase of any new Home Heating System.*

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Spring HVAC


a $159 Value*

Tune up your HVAC equipment yearly.

Just as a tune-up for your car can improve your gas mileage, a yearly tune-up of your cooling and heating system can improve efficiency and comfort.

14 Point Precision Cooling Tune Up

  1. Lubricate all moving parts.
  2. Check operating pressures and temperatures.
  3. Clean or replace air filters (provided by customer).
  4. Measure refrigerant superheat/subcooling to fine-tune its charge.
  5. Flush condensate drain to protect against overflow.
  6. Clean outdoor condenser coil.
  7. Clean and check blower motor (and belt if applicable).
  8. Test temperature drop at return and supply air. Adjust blower speed as needed.
  9. Safety test all controls for proper operation.
  10. Check voltage and amperage in all motors. Test for worn bearings.
  11. Check condition of compressor contacts.
  12. Inspect start and run capacitors and relays for bulges, rust and leaks.
  13. Check and safety test all wires and connections.
  14. Inform customer of equipment condition. Recommend necessary repairs or comfort improvements.

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John Duffy is the most trusted name in heating, air conditioning, and heating oil services in northern
and central New Jersey.

Explore Our Service Map

Office Address
465 Mulberry Street, Newark, NJ 07114

Mailing Address
P.O. Box 5610, Newark, NJ 07105

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