Comfort, engineered for every season on Long Island.
From the first cold snap in October to the humid afternoons of July, LI Heating & Air keeps Long Island homes and businesses at the perfect temperature. Expert installation, honest diagnostics and same-day repairs — delivered by licensed technicians who treat your home like their own.
Indoor climate, at a glance
Real comfort is measurable. We design, tune and verify every system so your home holds its target — quietly, efficiently, year round.
- Load-matched equipment selection
- Duct diagnostics and sealing
- Smart thermostat integration
- Indoor air quality upgrades
Full-service heating, cooling and clean-air solutions.
Whether you're replacing a tired furnace, chasing down a stubborn refrigerant leak, or simply want healthier air inside your home, our teams handle the entire job — from engineering assessment to commissioning and aftercare.
Heating installation & replacement
High-efficiency furnaces, boilers, and heat pumps specified for your home's real load — not the generic size on a catalog page.
- Manual J load calculations
- Variable-speed modulating equipment
- Rebate and incentive paperwork handled
Air conditioning service
Split systems, ductless mini-splits and central AC — installed, tuned and repaired with refrigeration-grade precision.
- System design and ductless zoning
- Refrigerant leak detection
- Compressor and coil replacement
Emergency repair
No heat in January is not a waiting game. Our service vans are stocked and dispatched across Long Island seven days a week.
- Rapid diagnostic visits
- Fully-stocked trucks on the road
- Upfront, approved pricing
Preventive maintenance
Annual tune-ups that cut energy bills, prevent mid-winter breakdowns and extend the life of expensive equipment.
- Multi-point inspection checklist
- Coil cleaning and filter service
- Priority scheduling for members
Indoor air quality
Whole-home filtration, humidification and ventilation that help with allergies, dry winter air and everyday comfort.
- HEPA and media filtration
- UV and air purification
- Humidifiers and dehumidifiers
Smart thermostat & controls
We install and program smart controls that learn your routine and quietly shave dollars off every energy statement.
- Nest, Ecobee and Honeywell
- Multi-zone balancing
- Seasonal schedule tuning
Built on Long Island. Trusted in every season.
LI Heating & Air began as a two-van operation out of a garage in Suffolk County more than twenty years ago. Today we run a full fleet of service and installation vehicles across Nassau and Suffolk, but we still answer the phone the same way we always have — a real person, a straight answer and a technician who shows up when we said he would.
Our approach is simple: we measure before we sell, we explain before we repair, and we test after we install. That discipline is why so many Long Island families call us back for a second system, or send us to a neighbor. Heating and cooling is a long-term relationship, and we take the long view.
Four steps from first call to lasting comfort.
No surprises, no guesswork — just a clear, documented path from the thermostat you have to the one you deserve.
Consult & measure
We walk your home, measure the load, inspect existing ductwork and listen to how you actually use each room.
Design & quote
You get equipment options, not a single hard-sell SKU. Every quote lists efficiency ratings, financing and available rebates.
Install & test
Certified installers set the system, balance airflow, commission refrigerant charge and confirm your target temperatures.
Care & support
We register warranties, schedule your first tune-up and remain one call away for the life of the equipment.
Reasons Long Island keeps our number saved.
We're not the biggest HVAC contractor on the island — and that's exactly the point. We're sized so every installation gets a senior technician and every customer gets a name, not a ticket number.
Honest diagnostics
If a $250 repair will give you three more seasons, we will tell you that — even when a full replacement is more profitable for us.
Local knowledge
We know Long Island: the coastal humidity, the older housing stock, the wind off the Sound. Our recommendations are tuned to those realities.
Same-day service
Our trucks carry the parts that fail most. Most repairs are finished the same day, not booked into next week.
Real warranties
We register manufacturer warranties on your behalf and back our labor with our own written guarantee.
By the numbers
Behind every number is a household that chose to trust a small local company over a national brand — and kept choosing us. That's the metric we actually care about.
What our neighbors say.
Reviews from real Long Island homes and businesses — no scripts, no stock photos.
"Our furnace died on the coldest weekend of the year. They had a technician at the house within a few hours, diagnosed a failed inducer motor and had us warm the same evening. Fair price, clean work."
"We replaced a 20-year-old AC and the whole process was smooth. They measured the house properly instead of just swapping in the same size unit, and our electric bill is noticeably lower."
"I manage a small office building and they keep three rooftop units running with annual maintenance. Professional, on schedule, and they always explain what they found in plain English."
News & seasonal tips.
Practical advice, seasonal reminders and company updates from the LI Heating & Air team.
Let's make your home comfortable.
Tell us what's going on — a system that's struggling, a space that never quite cools, or a planned upgrade. We'll get back to you within one business day with next steps.