If your furnace is struggling to keep up as the weather turns colder, you are probably asking the same question we hear every October: how much is this actually going to cost? Here is a straightforward answer, without the sales pitch.
Typical Furnace Replacement Costs in St. Louis
Most homeowners in the St. Louis area pay somewhere between $3,800 and $9,500 for a full furnace replacement, installation included. Where you land in that range depends on a few things:
- Furnace size and efficiency. A standard 80% AFUE furnace costs less upfront than a high-efficiency 95%+ model, but the high-efficiency unit usually pays some of that difference back through lower gas bills over time.
- Fuel type and existing setup. Gas furnaces are the local standard, and swapping like-for-like is simpler and cheaper than switching fuel types or upgrading ductwork.
- Home size and ductwork condition. A larger home, or one with ducts that need repair or modification, adds to labor and materials.
- Permits and removal. Local permitting and hauling away the old unit are typically built into a reputable quote, so ask upfront if they are not.
Repair or Replace? A Quick Gut Check
If your furnace is under 10 years old and the repair estimate is less than a third of replacement cost, repair usually makes sense. Once a furnace passes the 15-year mark, needs a second repair in two years, or the repair quote creeps toward half the cost of a new system, replacement is almost always the better long-term value. The U.S. Department of Energy’s ENERGY STAR program has a helpful breakdown of efficiency ratings if you want to compare models before you buy.
Getting an Accurate Number for Your Home
National averages are a starting point, not a quote. The only way to know your real cost is an in-home assessment that accounts for your furnace’s age, your ductwork, and your home’s actual heating load. JLM HVAC offers free, no-pressure furnace replacement estimates across St. Louis County, St. Charles County, and Jefferson County, including homeowners in Brentwood, where we provide heating and cooling installation and repair year-round.
If you are also comparing repair costs first, our team can walk you through both options honestly so you choose the one that makes sense for your home and your budget, not just the one that is easiest to sell.
Ready for a Straight Answer on Your Furnace?
Call JLM HVAC or request a free estimate online. We will look at your specific system, give you real numbers, and never push a replacement you do not need.
