What Drives the Cost of a Furnace Replacement

How much does it cost to replace a furnace for a 2000 sq ft house?

We do not publish a figure for a 2,000 square foot house, because square footage alone does not set the price. Needed size, efficiency, venting, gas line and ducts do, and two same-size houses can land far apart.

The way to get your number is the free estimate. We look at the house and the existing furnace, work out the size, check the venting and the ducts, and give you the price in writing with each of those as its own line.

What is the labor cost to install a furnace?

Labor varies most from house to house, so we price it from the house, not a rate card. A furnace in an open basement with a good side wall for the vent is a straightforward day. The same furnace in a tight closet or attic, or needing new venting, gas or duct work, takes longer and more hands.

• Removing the old furnace and getting it out of the house
• Setting the new furnace and connecting it to the ducts
• The gas connection and the leak test, by a licensed gasfitter where the county requires one
• The venting, and a condensate drain on a high efficiency furnace
• The electrical connection and the thermostat setup
• The permit, the inspection and start-up with readings taken

On our written estimate the work is listed line by line, so you can see what the labor covers. The figure for your house comes from the visit, not from a phone call.

Size comes first, and bigger is not better

The furnace is sized from the house: square footage, insulation, windows, orientation and how leaky it is. An oversized furnace short cycles, wears out sooner and leaves rooms uneven. The old one is a clue, not an answer: plenty were oversized the day they went in.

Sizing is part of the free estimate. If a contractor quotes a furnace without asking about the house, they are guessing.

Efficiency changes the furnace and the venting

A standard efficiency furnace vents hot exhaust up a metal flue. A high efficiency condensing furnace runs cooler exhaust through plastic pipe out a side wall and produces condensate that needs a drain. The condensing furnace costs more to buy and uses less gas every month.

The venting is where the price can move most. If the old furnace shared a chimney with a water heater, removing it can leave the water heater venting badly, and that fix belongs on the estimate. No good side wall means a longer vent run. We check all of it on the first visit.

Gas and electrical

• The gas line has to be sized for the new furnace and tested after the connection is made
• In Montgomery and Prince George's counties the gas work is done by a WSSC Water licensed gasfitter, and the number goes on the paperwork
• A new blower motor can need a dedicated circuit the old one did not have
• A furnace in a finished basement or a closet needs combustion air, and sometimes that means a vent that was never there

The ductwork decides how well it works

A new furnace pushing air through leaking, undersized or crushed ducts heats the basement and the attic instead of the rooms. We inspect the ducts before ordering, and small returns or a leaking trunk go on the estimate as their own line.

In a lot of the older housing inside the Beltway, the ducts were added decades after the house was built and sized for a different furnace. That is the usual reason the price of a replacement is more than the furnace itself.

Permit, removal and start-up

• The mechanical permit is part of the job and part of the price, not an extra
• The old furnace is removed and disposed of
• The new furnace is started up with readings taken, and the thermostat is set up for it
• You leave with the model and serial numbers, the warranty paperwork and the written scope matching what you approved

A new furnace comes with the manufacturer's equipment warranty under their terms, and our labor installing it is warranted for 60 to 90 days, depending on the job.

Repair or replace

If the furnace is under ten years old and this is its first failure, repair it. If it is past fifteen, if the heat exchanger is cracked, or if it has needed work in each of the last few winters, price the replacement. We give both numbers side by side. The guide on when to replace a furnace goes through the signs.