Furnace Installation and Replacement in Medford, NY
When your furnace struggles to keep up on the coldest Long Island nights — cycling constantly, making unusual noises, or leaving cold spots throughout your home — it is more than an inconvenience. An aging or failing furnace drives up your energy bills, puts your family's comfort at risk, and can even create safety concerns with outdated heat exchangers or faulty ignition systems. If your current system is over 15 years old or needs frequent repairs, replacement is often the smarter investment.
Central Air Systems has been installing and replacing furnaces across Long Island for 37 years. As a Lennox Premier Dealer — the first on Long Island — we carry high-efficiency gas and electric furnaces from Lennox and Bosch that are built to handle our region's demanding winters. Our NATE Certified technicians handle everything from the initial load calculation to the final safety check, and we back every installation with manufacturer warranties and our own commitment to quality workmanship.
How We Handle Your Furnace Installation
Every furnace installation we perform follows a structured process designed to get the sizing, airflow, and safety details right the first time. Cutting corners during installation leads to short equipment life, higher utility costs, and callbacks — so we do not skip steps.
Our technicians start with a thorough evaluation of your home. We measure square footage, inspect insulation levels, check window quality, evaluate existing ductwork condition, and factor in your home's orientation. Using Manual J load calculations, we determine the exact heating capacity your home requires so you are not paying for an oversized system or left shivering with one that is too small.
Based on the assessment, we walk you through your options. We carry the full Lennox Signature Collection, Lennox Merit and Elite series, and Bosch high-efficiency models. We explain the differences between single-stage, two-stage, and modulating furnaces so you can make an informed decision that fits your budget and comfort preferences.
Your new furnace is only as effective as the ductwork delivering the heated air. Before installation day, we inspect your existing ducts for leaks, damage, and sizing issues. If modifications are needed, we address them before the new equipment goes in. Proper duct preparation is one of the most overlooked steps in furnace installation, and it directly affects efficiency and comfort.
On installation day, our NATE Certified crew arrives with everything needed to complete the job. We remove and dispose of your old equipment, position and connect the new furnace, verify gas line connections (for gas furnaces), wire the thermostat, and ensure proper venting. We follow all manufacturer specifications and local building codes throughout the process.
After installation, we run the system through a full cycle to confirm ignition, airflow, temperature rise, and safety controls are all operating correctly. Before we leave, we walk you through thermostat operation, filter locations, and maintenance schedules so you know exactly how to get the most from your new system.
We stand behind every furnace we install. If something is not right, we come back and make it right.
When Should You Replace Your Furnace?
Deciding between another repair and a full replacement is not always straightforward. Here are the factors our technicians evaluate when helping homeowners make that call.
If you are dealing with any of these situations, contact our team for an honest assessment. We will tell you whether repair or replacement makes more sense for your home.
Starting Price Ranges
Use these starting ranges to plan your project. Final pricing depends on equipment selection, the condition of your ductwork and electrical, permits, and removal of the old system. We provide every customer with a written, no-obligation quote.
Gas Furnace Replacement
High-efficiency gas furnaces by heating capacity
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45,000 BTU Furnace
Smaller homes and condos — approximately 1,000–1,400 sq ft
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70,000 BTU Furnace
Average-size Long Island homes — 1,400–2,000 sq ft
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90,000 BTU Furnace
Larger homes or homes with higher heat loss — 2,000–2,600 sq ft
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110,000 BTU Furnace
Large or older, less-insulated homes — 2,600+ sq ft
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Pricing shown is a general starting range for typical Long Island installations. Final pricing depends on equipment selection, ductwork condition, electrical work, permits, and removal of the old system. Contact us for a free, no-obligation quote tailored to your home.
The Brands Behind Your New Furnace
We have spent decades working with the industry's top furnace manufacturers. Each brand brings specific strengths to the table, and our experience with all three lets us recommend the right fit based on your home, your budget, and your priorities.
Lennox
As Long Island's first Lennox Premier Dealer, we have installed more Lennox furnaces in this region than most contractors will see in a career. The Dave Lennox Signature Collection includes some of the quietest, most efficient gas furnaces on the market, with AFUE ratings up to 98.7%. The SLP99V model features a variable-speed blower and modulating gas valve for precise temperature control and whisper-quiet operation. For homeowners who want reliable performance without the premium price point, the Lennox Merit and Elite series deliver strong efficiency and dependable comfort.
Bosch
As Bosch Platinum Pros, we install and service their full line of residential furnaces. Bosch systems are engineered for consistent, energy-efficient heating with a focus on durability. Their furnaces pair well with Bosch heat pumps for homeowners considering a dual-fuel setup that maximizes efficiency across Long Island's variable winter temperatures.
Mitsubishi Electric
As Mitsubishi Electric Diamond Dealers, we also offer solutions for homes that benefit from ductless or hybrid heating approaches. While Mitsubishi is best known for ductless mini-splits, their hyper-heating technology can supplement a furnace system in zones where ductwork does not reach, giving homeowners complete coverage without major renovation.
Our team has earned the Lennox Centurion Award and the Lennox Partner of the Year Award — recognition reserved for the top-performing dealers in the country. These awards reflect our installation quality, customer service, and long-term commitment to the brands we represent.
What Makes Us Different
37 Years of Experience
We have been installing and replacing furnaces on Long Island since 1989, and that experience shows in every job we complete.
NATE Certified Technicians
Every installer on our team holds current NATE certification, the industry's most respected credential for HVAC technicians.
Lennox Premier Dealer
Long Island's first Premier Dealer, recognized for installation quality, customer satisfaction, and ongoing technical training.
Flexible Financing
0% interest for 60 months through Service Finance makes a new high-efficiency furnace accessible without the full upfront cost.
Upfront Pricing
We provide detailed written estimates before any work begins. No surprises, no hidden charges after the fact.
Local to Medford
Our team lives and works in the same communities we serve. When you need us, we are close by and ready to respond.
Finance Your New Furnace
A new high-efficiency furnace is one of the best investments you can make in your home's comfort and energy savings — and it does not have to strain your budget. Through our partnership with Service Finance, qualified homeowners can take advantage of 0% interest for 60 months, making it easy to upgrade without paying the full cost upfront.
The application process is simple and can be completed online or in person. Most homeowners receive a decision within minutes, and our team will walk you through the available plans so you can choose the option that works best for your household. Replacing an old, inefficient furnace now means lower energy bills from day one, often offsetting a significant portion of the monthly payment.
Furnace Maintenance Plans
Getting the most out of your new furnace means keeping it maintained. Our maintenance plans include annual tune-ups performed by NATE Certified technicians who inspect burners, heat exchangers, blower motors, electrical connections, and safety controls. Plan members also receive priority scheduling during peak heating season when demand is highest.
Regular maintenance protects your manufacturer warranty, extends equipment life, and catches small issues before they become expensive repairs. Long Island winters put serious demand on heating systems, and a well-maintained furnace runs more efficiently, lasts longer, and keeps your home safer throughout the season.
Our home base is Medford, and from there we serve homeowners throughout Suffolk County and beyond. Whether you are in a waterfront community dealing with salt air corrosion on outdoor components or in an inland neighborhood with older homes that need careful ductwork modifications, our team brings local knowledge to every furnace installation.
We have installed furnaces in homes of every size and age across Long Island — from post-war Cape Cods with tight mechanical closets to modern new construction with open floor plans. That range of experience means we can adapt to the specific challenges your home presents, not just follow a one-size-fits-all playbook.
Frequently Asked Questions
Most furnace replacements are completed in a single day. A straightforward swap — removing the old unit and installing a new one in the same location — typically takes four to eight hours. If ductwork modifications or a fuel type conversion are involved, the timeline may extend slightly, but we will outline the full scope before work begins.
Furnace sizing depends on your home's square footage, insulation quality, window efficiency, ceiling height, and layout. We perform Manual J load calculations to determine the right capacity. An oversized furnace short-cycles and wastes energy, while an undersized one cannot keep up on the coldest days. Proper sizing is one of the most important parts of the installation process.
High-efficiency furnaces with AFUE ratings of 95% or higher convert nearly all the fuel they consume into heat. If your current furnace has an AFUE of 80% or lower, upgrading can reduce your heating fuel consumption noticeably. The exact savings depend on your home's size, insulation, and heating habits, but most homeowners see a meaningful reduction in their winter energy bills.
A single-stage furnace runs at full capacity whenever it is on. A two-stage furnace has a low and high setting, running on low most of the time for quieter, more efficient operation. A modulating furnace adjusts its output continuously in small increments, maintaining the most consistent temperature and the lowest operating noise. We carry all three types and can help you decide which matches your comfort preferences and budget.
Yes. Through Service Finance, we offer 0% interest for 60 months on qualifying furnace installations. The application is quick, and most homeowners receive approval within minutes. Visit our financing page for details or ask your technician during your in-home consultation.
In many cases, yes. However, if your current thermostat is older or lacks features like programmable scheduling or Wi-Fi connectivity, upgrading to a modern thermostat allows you to take full advantage of your new furnace's efficiency features. We will evaluate compatibility during the assessment and recommend an upgrade only if it makes a difference in performance or convenience.
We recommend annual maintenance before each heating season. A tune-up includes inspecting the heat exchanger, cleaning burners, checking the blower motor, testing safety controls, and verifying proper airflow. Regular service keeps your system running efficiently, extends its life, and maintains your manufacturer warranty. Our maintenance plans make it easy to stay on schedule.
We install furnaces from Lennox, Bosch, and Mitsubishi Electric. As a Lennox Premier Dealer, Bosch Platinum Pro, and Mitsubishi Diamond Dealer, we have factory training and direct support from all three manufacturers. We will recommend the brand and model that best fits your home's heating needs, your efficiency goals, and your budget.
Let’s Get Started
Replacing your furnace is a decision that affects your home's comfort, safety, and energy costs for the next 15 to 20 years. At Central Air Systems, we approach every installation with that long-term perspective — selecting the right equipment, sizing it properly, and installing it to manufacturer specifications so it delivers reliable performance season after season.
We have been doing this work across Long Island for 37 years, and our reputation is built on getting the details right. From your first phone call through your final walkthrough, you will work with experienced, NATE Certified professionals who take pride in their craft. If you are ready to discuss your furnace replacement options, we are here to help.
37 years of trusted service — serving Long Island homeowners since 1989 with dependable heating solutions
NATE certified technicians — our installers hold the HVAC industry's highest professional certification
Premier dealer status — Lennox Premier Dealer, Bosch Platinum Pro, and Mitsubishi Diamond Dealer
0% financing available — affordable monthly payments through Service Finance with no interest for 60 months
Transparent pricing — detailed written estimates provided before any work begins, with no hidden fees
Locally based in Medford — headquartered at 22A Scouting Blvd, Suite 2, Medford, NY 11763
