Furnace replacement & installation in St. Paul, MN

Sized from a load calculation, not a guess

A furnace that is too large heats the house in short bursts, then shuts off. A furnace that is too small runs constantly on the coldest nights. Both waste fuel and wear out parts sooner.

We size your new furnace from a load calculation that accounts for your insulation, windows, air leakage and ductwork. The size of the old furnace is not a reliable guide. Many older homes have been insulated or had windows replaced since the old furnace went in.

We also ask which rooms run cold today and how you use each space. Leaky or undersized ducts can cause uneven heat even with a new furnace. We check the ductwork before we recommend a size.

The U.S. Department of Energy guide to furnaces and boilers recommends improving insulation and windows before you replace a furnace. After those upgrades, a smaller furnace may heat your home well.

What the efficiency rating means

Every new furnace carries an AFUE rating, short for Annual Fuel Utilization Efficiency. It tells you how much of the fuel's energy becomes heat in your home over a typical year. A 90% AFUE furnace turns about 90% of its fuel into heat, and about 10% is lost.

According to the Department of Energy, older low-efficiency systems run at 56% to 70% AFUE. High-efficiency condensing furnaces range from 90% to 98.5% AFUE. In cold climates like ours, the Department of Energy suggests choosing the highest efficiency available.

ENERGY STAR certified gas furnaces for northern states are up to 18% more efficient than baseline models. As a Daikin ComfortPro certified dealer, we can show you which Daikin furnaces fit your home and budget.

What installation involves

A high-efficiency furnace uses sealed combustion. It draws outside air for the burner and sends its exhaust directly outdoors. That exhaust is acidic, so the furnace may need a new vent or a lined chimney.

If your water heater shared a chimney with the old furnace, its venting may need changes too. Before we quote, we check the vent path, condensate drain, gas line, electrical connection and ductwork. Your written quote lists the work your home needs, with no pressure to decide on the spot.

Most replacements are completed in a single day. Our certified, background-checked technicians protect your home, test the system thoroughly and show you how everything works before they leave.

Gas piping and combustion venting are not do-it-yourself work. Never move a gas line or reconnect a vent pipe yourself, because a mistake can cause a gas leak or carbon monoxide in your home.

Rebates and financing in 2026

If Xcel Energy supplies your gas, Xcel Energy’s Minnesota rebate summary lists rebates for a qualifying gas furnace in an existing home: $200 for 95% AFUE, $300 for 96% AFUE and $400 for 97% AFUE. If another utility serves your home, check its programs.

The application must be postmarked by September 30 of the year after installation. You need a dated invoice or receipt showing the manufacturer, model and serial number; estimates are not accepted. An AHRI certificate is highly recommended.

The federal Energy Efficient Home Improvement Credit no longer applies to a new furnace. The IRS rules for the home improvement credit limit it to property placed in service before December 31, 2025. You can spread out the cost with our financing options for new equipment.

Repair or replace?

Age is one factor, but not the only one. Consider replacement when a furnace is more than 15 years old and needs a major part. Frequent repairs, rising bills and rooms that never warm up also point toward a new system.

If your central air conditioner is also near the end of its life, ask about replacing both together. The furnace blower moves air for both systems, so matching them can make sense.

We give you both options in writing, and we will tell you when a repair makes more sense. Once your new furnace is in, a furnace tune-up each heating season helps it run safely and efficiently.

Signs it’s time for a new furnace

• It’s more than 15 years old
• Repairs are getting more frequent
• Heating bills keep rising
• Some rooms never warm up
• It’s noisier than it used to be

Common questions

Sources

• U.S. Department of Energy — Furnaces and Boilers
• ENERGY STAR — Furnaces
• Xcel Energy — Minnesota residential rebate summary
• Xcel Energy — Minnesota residential HVAC rebate application
• IRS — Energy Efficient Home Improvement Credit