What makes John Duffy the best in HVAC?

Our experience, customer service and quality.


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.


Our Special Offers

Get the best value with John Duffy.

Get a FREE NEST
Wi-Fi Thermostat

Wi-Fi Nest Learning Thermostat

A $450.00 value!

with the purchase of any new Home Heating System.*

View Offer

Spring HVAC
Tune-Up
Special

$89

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.

View Offer

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




Warning: Unknown: open(/home/content/14/6248714/tmp/sess_mifepe4unb9sk9r27kqtl72460, O_RDWR) failed: No such file or directory (2) in Unknown on line 0

Warning: Unknown: Failed to write session data (files). Please verify that the current setting of session.save_path is correct () in Unknown on line 0