Furnace Installation in Lenexa, KS

A new furnace in Lenexa has to deliver on the coldest night of a Johnson County winter — a roughly 13°F design low — whether it’s heating a historic Old Town home or a large new build out west. 7th Degree Heating and Air installs gas and electric furnaces across all of Lenexa, sized with a load calculation, matched to the home, and started up with combustion verified and carbon monoxide checked. We reach eastern Lenexa quickly from our Leawood base and cover the western subdivisions too.

Right for Old Lenexa or New Lenexa

The city’s split shapes the furnace decision. A historic Old Town home may have an aging furnace in a tight space with original ductwork, where a careful replacement and airflow attention matter. A large new west-Lenexa build is tightly sealed and well-insulated, carrying a lower heat-loss load that demands honest sizing — matching the old nameplate often oversizes it. We run an ACCA Manual J calculation, match equipment with Manual S, and walk you through the tradeoff between a standard 80% AFUE furnace and a high-efficiency 90%+ condensing unit. For larger newer homes, we’ll also discuss two-stage or modulating furnaces paired with zoning for even comfort across floors.

What Our Lenexa Installation Includes

• Manual J load calculation sized to your home and its construction era.
• Staging guidance — single-stage, two-stage, or modulating, matched to the home (and zoning where it helps).
• Code-compliant venting — correct flue or PVC for the furnace type.
• Gas line and pressure verification on your natural gas service.
• Old furnace removed, permits pulled through the Johnson County building department, warranty registered.
• Combustion verified on startup — manifold pressure set, carbon monoxide measured air-free.

Frequently Asked Questions

What size furnace does my Lenexa home need?

The size a Manual J load calculation says you need, not the old furnace’s size. We measure heat loss and size to match. In Lenexa that matters because a historic Old Town home and a large new west-side build carry very different loads — and newer tight homes are easy to oversize if you go by square footage.

Should I get an 80% or a 90%+ AFUE furnace?

AFUE is how much fuel becomes usable heat. An 80% furnace costs less up front and uses standard metal venting; a 90%+ condensing furnace captures more heat, vents through PVC, needs a condensate drain, and saves on gas over time. Which one pencils out depends on your home and how long you’ll stay — we’ll run the comparison.

Do I need a two-stage or modulating furnace in my larger Lenexa home?

For a larger newer home, often yes — a two-stage or modulating furnace runs at lower output most of the time, giving steadier, more even heat and quieter operation, and it pairs well with zoning to fix a hot-or-cold floor. For a smaller or simpler home, a single-stage furnace is perfectly good. We match the equipment to the home.

Do you verify safety after installation?

Always. We set manifold gas pressure to spec, measure carbon monoxide air-free at startup, confirm the venting draws correctly, and verify the heat exchanger and safeties. A furnace is a combustion appliance, and we don’t call an install finished until it’s confirmed safe.

How long does a furnace installation take?

A standard replacement is usually a single day. Switching efficiency types (which changes the venting), relocating the unit, or adding zoning or gas/electrical work can extend it. We give you a realistic timeline with the quote.

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Contact 7th Degree Heating and Air

Serving Lenexa and all of eastern Johnson County, including Leawood, Overland Park, Prairie Village, Mission, and Merriam, with 24/7 emergency service.

• Emergency Line (24/7): (913) 354-6552
• Address: 12720 Catalina St, Leawood, KS 66209
• Email: info@7thdegreeheatingandair.xyz
• Johnson County Class “DM” Mechanical License: DM-24-11873
• EPA Section 608 Universal: EPA-608-U-457921

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Office Hours

• Emergency Service: 24 hours a day, 7 days a week
• Office Staff: Monday – Saturday, 9:00 AM – 5:00 PM
• Sunday: By appointment
• Closed: Holidays (emergency line always active)