HVAC Contractor in Onset, MA

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Fast, reliable HVAC service when your system fails and comfort matters most.

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Professional HVAC Services Onset

What Working Systems Actually Give You

You get your house back to comfortable. No more bundling up indoors during winter or sweating through summer nights because your system decided to quit.

When your HVAC system works right, you stop thinking about it. Your energy bills stay predictable instead of spiking every month. You sleep better knowing your family stays comfortable no matter what the weather throws at you.

The real benefit isn’t just a working furnace or air conditioner. It’s having one less thing to worry about in a world that gives you plenty to stress over already.

Trusted HVAC Company Onset

We've Seen Every Problem Before

Dempsey Energy has built relationships with over 12,000 homeowners throughout Plymouth County. That’s not an accident.

We focus on getting things right the first time and staying connected with customers through our Dempsey Comfort Club. We understand that HVAC problems don’t wait for convenient times, which is why we’ve structured our business around being there when you actually need us.

HVAC Repair Process Onset

Here's How We Handle Your Call

You call with a problem, and we schedule a technician who actually shows up when promised. No waiting around all day wondering if someone’s coming.

Our technician diagnoses what’s wrong and explains it in plain English. You get a clear picture of your options – whether that’s a simple repair, a part replacement, or a bigger conversation about system replacement.

Once you decide how to move forward, we handle the work professionally and clean up after ourselves. You get a system that works and a clear understanding of what was done.

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Complete HVAC Services Onset

Everything Your System Needs Covered

Dempsey Energy handles the full range of heating and cooling needs for Onset area homes. Emergency repairs when your system fails, routine maintenance to prevent problems, and complete installations when it’s time for a new system.

Our technicians work on all major brands and system types. Whether you’re dealing with a furnace that won’t start, an air conditioner blowing warm air, or a system that’s just not keeping up anymore, we have the experience to handle it.

The Dempsey Comfort Club gives you priority scheduling and ongoing maintenance to catch problems before they become emergencies. It’s designed for homeowners who’d rather prevent issues than deal with them at the worst possible time.

How quickly can you respond to emergency HVAC calls in Onset?

Emergency response times depend on the day and current call volume, but Dempsey Energy prioritizes urgent calls where heating or cooling systems have completely failed. During extreme weather, we understand that a broken furnace or air conditioner isn’t just inconvenient – it’s a real problem for your family’s comfort and safety. Dempsey Comfort Club members get priority scheduling, which means they move to the front of the line when emergencies happen. If you’re dealing with a complete system failure, call as soon as possible so we can get someone out to diagnose and fix the problem.

Should I repair my old HVAC system or replace it entirely?

This depends on your system’s age, the cost of repairs, and how often you’re calling for service. If your system is over 15 years old and needs a major repair that costs more than half of a replacement, replacement usually makes more sense. Systems that break down multiple times per year are telling you something – they’re wearing out. A good technician will give you honest advice about whether a repair will actually solve your problem or just buy you a few more months. Our technicians will walk you through the math so you can make the decision that makes sense for your situation and budget.

What's included in regular HVAC maintenance service?

Regular maintenance includes cleaning and inspecting all the components that keep your system running efficiently. This means checking and replacing filters, cleaning coils, inspecting electrical connections, testing safety controls, and making sure everything operates the way it should. Our technician will also catch small problems before they become big, expensive ones. For heating systems, this includes checking the heat exchanger, burner, and venting. For cooling systems, we’ll check refrigerant levels, clean the condenser, and make sure airflow is proper. Maintenance visits typically take about an hour and can prevent most emergency breakdowns.

Why is my energy bill so high even though my system seems to work?

A system that “works” isn’t necessarily working efficiently. Dirty filters, clogged coils, low refrigerant, or worn components can make your system work much harder to heat or cool your home. It’s like driving with the parking brake on – everything seems fine until you realize how much extra energy you’re wasting. Older systems also lose efficiency over time, especially if they haven’t been maintained properly. An HVAC technician can measure your system’s efficiency and identify what’s causing high energy bills. Sometimes simple maintenance fixes the problem. Other times, you’ll need to decide whether ongoing high bills justify upgrading to a more efficient system.

Do you service all brands of heating and cooling equipment?

Yes, our technicians work on all major HVAC brands and system types. Whether you have a traditional furnace and central air setup, a heat pump system, ductless mini-splits, or boiler heating, we have the experience and tools to service it properly. We stock common parts for most systems and can source specialized components when needed. The brand on your equipment doesn’t matter as much as having technicians who understand how different systems work and can diagnose problems accurately. Our experience with thousands of local installations means we’ve likely worked on your exact system type before.

What should I do if my heating system stops working completely?

First, check your thermostat settings and make sure it’s set to heat mode at the right temperature. Check your circuit breaker to see if it’s tripped, and make sure your furnace switch is on. If you have a gas system, verify that other gas appliances are working. Check your air filter – a completely clogged filter can shut down some systems. If these basic checks don’t solve the problem, call for service rather than trying to fix it yourself. Modern HVAC systems have safety controls that shut them down when something’s wrong, and overriding these controls can be dangerous. A qualified technician can safely diagnose why your system shut down and get it running again.

Local Resources

Onset, MA is located in Plymouth County in Massachusetts State