How much does an electric furnace cost?

One figure against two

Fixr's top end is $3,800 below the other two, our subtraction, and less than half of their maximum. On most topics in this section we would take the two that agree over the one that differs.

Here we would not, and the reason is in their own small print.

Why we do not count that agreement twice

This Old House prints this note on its furnace guide:

Note: The cost data in this guide is based on estimates from HomeAdvisor, unless otherwise noted.

Bob Vila's furnace guide attributes its figures to Angi.

Our reading, marked as ours. Two guides giving the identical range of $2,000 to $7,000, both sourcing their cost data from contractor marketplaces rather than measuring it themselves, is one figure printed twice. It is not two independent confirmations, and we are not going to present it as one.

We found the same pattern on our evaporator coil page, where two publishers printed three identical figures and both disclosed Angi as a source. We found the opposite on our boiler page, where close agreement survived the check because neither publisher sourced from the other's well. This is the first kind.

Fixr states it builds figures from its own pricing databases, licensed contractors and industry experts, which makes it the one genuinely separate measurement on this page. Its figures are also the most specific: the $2,400 average describes a 68,000 BTU unit, which no other guide tells you.

What we would use. Fixr's $1,600 to $3,200 for a straightforward replacement, and the knowledge that $7,000 jobs exist, because they plainly do. Our furnace page has what the sources say about furnaces generally, and the same two publishers reprint the same marketplace figure on our oil furnace page. Our propane furnace page covers the fuel with the widest spread of all.

The 100% efficiency trap

Fixr explains the difference between fuel types clearly:

Standard gas, propane, and oil units convert about 80% of their energy into heat, while high-efficiency units convert up to 98% of their fuel. The remaining fuel is burnt off as exhaust.

And for electric:

converts nearly 100% of its energy into heat.

An electric furnace has no exhaust and nothing burnt off, so almost everything the meter records becomes heat in the house.

Our reading, marked as ours, and this is the thing to take away. That number describes the appliance, not the bill. Efficiency tells you how much of the energy you bought becomes heat. It says nothing about what that energy cost. In most of the US, a unit of heat delivered as electricity costs considerably more than the same unit delivered as natural gas, which is why an electric furnace can be nearly perfect and still be the most expensive thing in the house to run.

We are not giving you a ratio, because it depends entirely on your local electricity and gas prices, and none of our sources publishes one. What we can tell you is that cheapest to buy and cheapest to own are different questions here, and the published guides only answer the first.

The machine that avoids that trap is the heat pump, which runs on the same electricity but moves heat instead of making it. Our how a heat pump works page explains why that lets it deliver more heat than the energy it consumes, and our heat pump vs furnace page prices it.

What size, and what that part costs

Fixr's sizing table, materials only:

Our arithmetic, marked as ours. Every row works out at 35 to 40 BTU per square foot, so this is another table that is one rule with the multiplication done for you, a pattern we have now found on the radiant floor, furnace and central air pages.

The useful part is the second column against the third: a unit at $600 to $1,400 inside an installed job averaging $2,400 means the furnace is between a quarter and nearly three fifths of what you pay. Fixr also warns that electric furnaces come in 7,000 to 10,000 BTU increments, so the available sizes may not match your calculation exactly, and advises choosing the closest size rather than undersizing.

What else that money could buy

Fixr puts three electric heating options side by side, materials only:

Our note: the heat pump band is wide enough to start below an electric furnace and end seven times above it, which is the whole argument in one row. Our heat pump page has the installed figures from two publishers.

Fixr's cheapest brand, Revolv, runs $600 to $850 and is described as a good-quality budget brand making small furnaces and units designed for manufactured homes.

Before you buy one

1. Ask what it will cost to run, not just to fit. Nearly 100% efficient is not the same as cheap, and no guide on this page answers the second question.
2. Get your electricity rate out and ask the installer to compare it against the fuel you use now.
3. Ask for the unit price separately. At a quarter to three fifths of the job, it is the comparable part of a quote.
4. Ask which BTU size, and accept that the increments are coarse. Closest size, not smallest.
5. Price a heat pump at the same time. It uses the same electricity supply and the same ducts, and on running cost it is the direct competitor.