Furnace Replacement & Installation in Northern Virginia & Maryland

Should You Replace Your Furnace?

Most homeowners ask us the same question, usually standing next to a furnace that’s limping through another winter: repair it again, or replace it? Here’s a simple rule of thumb — the $5,000 rule for furnaces:

Take your furnace’s age and multiply it by the quoted repair cost. If the result is over $5,000, replacement is generally the better financial move.

It works because furnace repair costs don’t rise in a straight line — they snowball. An igniter ($150 – $300) one winter, a control board ($200 – $600) the next, then a blower motor ($400 – $1,500), per our cost guide. The rule draws a clean line through that curve.

Factual criteria that back it up:

• A 20-year-old furnace. Most furnaces are built for 15–20 years of service. At 20, yours is running on borrowed time — and likely at 80% AFUE or less while modern units reach 90%+. Parts get harder to find and more expensive. Plan the replacement on your schedule, not in an emergency.
• A 30-year-old furnace. Plan to replace it. Efficiency, safety controls and parts availability have all moved on since it was installed.
• Repair bills two or three winters in a row. You’re financing a new furnace in installments, without getting one.
• Gas bills climbing while your usage hasn’t changed — the unit is burning more fuel to make less heat.
• Uneven heat, loud operation, or a cracked heat exchanger: the last one is a carbon monoxide risk and an immediate replacement conversation.

Not sure where you land? Get a free written estimate. We’ll run the repair-vs-replace numbers with you, and if a repair makes more sense, see furnace repair. VA (703) 457-9028 · MD (301) 686-7129

Gas vs Electric Furnace (and When a Heat Pump Makes Sense)

Choosing your new furnace starts with fuel type. Here’s how they compare:

Gas furnaces cost less to run in most Northern Virginia and Maryland homes, produce hotter supply air, and heat quickly on the coldest nights. They need a gas line, proper venting/flue, and a bit more maintenance. If your home already has gas service, gas is usually the economical choice.

Electric furnaces cost less to install — no venting, no gas line, simpler equipment. They’re a solid fit for homes without gas service or smaller spaces. The tradeoff: electricity generally costs more per unit of heat, so monthly operating costs run higher. Here’s how electric furnaces work if you want the full picture.

The third option: a heat pump. If you’re replacing a furnace and thinking about your aging air conditioner, a heat pump heats and cools in one system — and pairs with a gas furnace in a dual-fuel setup that switches to gas only on the bitterest days. See heat pump installation for details.

We’ll quote whichever direction makes sense for your home — gas, electric, or heat pump — with the math to back it up.

Furnace Efficiency (AFUE) Explained

Furnace efficiency is measured in AFUE — Annual Fuel Utilization Efficiency. An 80% AFUE furnace turns 80 cents of every fuel dollar into heat; a 96% AFUE unit turns 96 cents into heat. That gap compounds over 15–20 years of gas bills.

You’ll choose between three operating styles:

• Single-stage. The furnace is either fully on or fully off. Lowest upfront cost, but wider temperature swings and more noise.
• Two-stage. Runs on low most of the time and kicks to high only on the coldest days. Quieter, more even heat, better efficiency — the sweet spot for most homes.
• Variable-speed (modulating). Adjusts output in small increments to match exactly what your home needs. The most comfortable and efficient option, and the best pairing for zoned systems.

The right call depends on how long you’ll stay in the home, your ductwork condition, and your budget. Our free estimate walks you through the payback math.

What Size Furnace Do I Need?

This is where most installations go wrong, and it’s the question that costs homeowners the most when it’s answered badly. An oversized furnace short-cycles — blasting heat, shutting off, blasting again — which wears parts faster and leaves cold spots. An undersized one runs constantly and still can’t keep up in January.

A common rule of thumb is 30–60 BTUs per square foot of living space (so a 2,000 sq. ft. home lands roughly in the 60,000–120,000 BTU range), but square footage alone isn’t the answer. Insulation, windows, ceiling height, air leakage, and ductwork condition all change the real number.

Our free in-home estimate includes a proper sizing assessment — measured, calculated, and matched to your home. VA (703) 457-9028 · MD (301) 686-7129

Preparing for Your New Furnace

A little prep makes the installation day smooth. Here’s what to do before our crew arrives — our full preparation checklist goes deeper:

• Clear 3 feet around the furnace on all sides — move boxes, shelving, and anything stored against it.
• Clear a path from your front door to the furnace (we’ll be carrying equipment through).
• Secure pets in a room away from the work area.
• Plan to be home: we’ll need you to approve placement details and walk through the finished install.
• Know your thermostat: if you’re upgrading it, decide ahead of time; we’ll calibrate whatever you choose.

Old-unit removal and cleanup are part of the job.

What Happens on Installation Day

Most furnace installations take one day. Here’s the sequence:

• Arrival and protection. The crew lays drop cloths and protects floors from the door to the furnace.
• Safe shutdown and removal. Gas and power are disconnected and the old unit is removed.
• New unit set. The furnace is positioned, connected to your ductwork, venting/flue, gas line, and electrical — everything sealed and secured to code.
• Thermostat and controls. Your thermostat is wired, calibrated, and tested with the new system.
• Startup and testing. We fire the unit and verify ignition, airflow, temperature rise across the heat exchanger, and every safety control.
• Walkthrough. We show you the filter location, thermostat basics, and maintenance schedule.

You get heat the same day, a clean work area, and paperwork in hand. Larger or more complex jobs can run into a second day — we’ll tell you upfront if yours will.

Furnace Replacement Cost

Let’s answer the big question directly: what is the average cost to replace a furnace? Based on our furnace installation cost guide, the average lands around $4,325, with most homeowners paying between $2,544 and $6,127.

Brand matters too — installed gas furnace costs by brand:

Old-unit removal typically runs $60 – $500, and most Northern Virginia and Maryland jurisdictions require a permit ($400 – $1,500) — permit needs and fees are listed in your written estimate.

Your exact number depends on your home’s size, ductwork, venting, and the efficiency tier you choose. That’s why our estimates are free and written. VA (703) 457-9028 · MD (301) 686-7129

Furnace Financing

A new furnace shouldn’t have to wait for the perfect budget month. AVS offers financing through Wells Fargo:

• 0% APR for up to 18 months on select units
• Zero-down plans available
• Subject to lender approval

And one more thing worth asking about: federal, state, and utility rebates and tax credits change regularly — ask us which rebates apply to your installation, and we’ll point you to what’s current.

Furnace Brands We Install

We install all major furnace brands and size every unit to your home:

Lennox · Bryant · Trane · Carrier · Goodman · York · Rheem · Amana · American Standard · Mitsubishi · Ameristar

Gas or electric, single-stage through variable-speed, we match the equipment to your home’s load, your ductwork, and your budget.

Why Homeowners Choose AVS for Furnace Installation

• Family-owned since 1991: More than 30 years of HVAC service in Northern Virginia and Maryland.
• Seen on ABC7 News: Anil Sareen of AVS Heating and Air Conditioning was interviewed on ABC7 News.
• Licensed in Virginia and Maryland: Virginia HVAC 2705039269A · Maryland HVAC 520714137895 · Maryland Home Improvement 4192876.
• Three local offices: Fairfax, VA · Falls Church, VA · Bethesda, MD.
• 4.8★ on Google: 354 reviews across our three offices.
• All brands serviced: Carrier · Trane · Lennox · Bryant · Goodman · Rheem · York · American Standard · Amana · Mitsubishi.

Commercial Furnace Installation

AVS also installs and replaces furnaces and heating systems in shops, offices and other commercial buildings across Northern Virginia and Maryland. See commercial HVAC installation, repair and replacement.