Comprehensive 24/7 HVAC Support, When You Need It Most

Rapid Response Time

From complete system failure to restoring optimal system performance, our emergency service team will get your HVAC systems up and running so you can get back to business. We are available 24 hours a day, 7 days a week, 365 days a year. Around the clock, we maintain a full emergency service crew, including supervisors and technicians.

Unique NYC Zoning System

Ensuring prompt response when you need it most, Donnelly dispatches our certified technicians according to a strategic zoning system throughout Manhattan. Along with a fleet of more than 100 branded service vehicles and over 30 on-foot technicians, our typical response time is among the fastest in the industry, allowing us to resolve your emergencies quickly and efficiently.

Manufacturer Certified Technicians

Our staff is trained and certified to work on all major manufacturers’ lines of HVAC equipment. In addition to these certifications, ongoing trainings are required for all staff to maintain and increase technical expertise in our industry.

Why Choose Donnelly Mechanical?

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30+ Years of Industry Leadership
Trusted by NYC’s top businesses for reliable HVAC solutions.

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Certified & Experienced Technicians
Trained in the latest industry standards and technologies.

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Customized Installations
Solutions tailored to your building’s size, usage, and energy needs.

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Regulatory Compliance & Safety Focus
Ensuring adherence to Local Law 97, ASHRAE, and EPA standards.

NYC’s Most Reliable Emergency HVAC Partner

Donnelly delivers the peace of mind that comes with 24/7 coverage and decades of expertise. When failure isn’t an option, we’re the ones to call.

Call 718-619-4384 now for immediate 24/7 HVAC assistance
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“A tripped circuit breaker located in the basement on the building caused our CRAC unit to go into a High-Temperature alarm and go down. Our Donnelly technician and his field supervisor responded right away. They were the absolute best. They were in constant communication with us, keeping us well informed, and were extremely professional as always. They truly represented Donnelly and what they stand for.”

Director of Business Affairs

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FAQ

We service all types of commercial HVAC systems, including rooftop units, chillers, boilers, air handlers, VRF/VRV systems, and more. Our experienced technicians are trained to diagnose and repair equipment from all major manufacturers.

We provide 24/7 emergency HVAC service with rapid response times throughout New York City. Our team is available around the clock to minimize downtime and restore system functionality as quickly as possible.

Yes. We offer customized maintenance and service agreements tailored to your company’s needs. These agreements help maintain peak efficiency, reduce downtime, and extend the lifespan of your HVAC equipment.

  • Contact our service department: Let us know you are a new customer.
  • Submit onboarding form: Fill out a brief form to set up your account.
  • Schedule a visit: A service coordinator will arrange for a technician to assess your system.
  • Initial troubleshooting: The technician will attempt to resolve the issue during the first visit.
  • Follow-up visit: If the issue cannot be resolved during the first visit, the technician will advise if a follow-up visit is needed for further troubleshooting.
  • Quote for repairs: If applicable, the technician will provide a quote with recommended repairs.

You can request emergency HVAC service by calling our 24/7 line at 718-886-1500. Our team will dispatch a certified technician to assess and repair your system as quickly as possible.

We are New York City’s premier mechanical contractor, trusted by over 1,700 companies for reliable HVAC service. Our benefits include:

  • Rapid Response Time:
    • From complete system failure to restoring optimal system performance, our emergency service team will get your HVAC systems up and running so you can get back to business.
    • Available 24 hours a day, 7 days a week, 365 days a year.
    • Around the clock, we maintain a full emergency service crew, including supervisors and technicians.
  • Unique NYC Zoning System:
    • Ensuring prompt response when you need it most, Donnelly dispatches our certified technicians according to a strategic zoning system throughout Manhattan.
    • With a fleet of more than 100 service vehicles and over 30 on-foot technicians, our typical response time is among the fastest in the industry, allowing us to resolve your emergencies quickly and efficiently.
  • Manufacturer Certified Technicians:
    • Our staff is trained and certified to work on all major manufacturers’ lines of HVAC equipment.
    • Ongoing trainings are required for all staff to maintain and increase technical expertise in our industry.
  • Executive Involvement:
    • Donnelly understands the importance of having access to the top, which is why our executive team is always available to help you with your Commercial HVAC Repair needs when you require resolutions as quickly as possible.

Regular preventive maintenance is the best way to prevent unexpected failures. Our customized maintenance agreements are designed to keep your HVAC system running at peak efficiency and reduce the likelihood of emergency repairs.

Getting started is easy. Contact us today to discuss your HVAC service needs by filling out the form below.