Replacing a 30-Year-Old Gas Furnace, Part 2: Vetting Contractors and Comparing Quotes

Photo by Vadim Babenko on Unsplash

Once Frank and I established our budget tiers and efficiency goals for replacing our 30-year-old gas furnace, we faced the next hurdle: finding the right HVAC contractor in Pennsylvania. Installing a high-efficiency furnace isn't just about buying a good piece of equipment; the quality of the installation determines system longevity, safety, and operating efficiency.

Here is how we navigated contractor interviews, evaluated line-item estimates, and chose the right installation team.

---

The Interview Process: Asking the Right Questions

We scheduled in-home visits with four licensed HVAC contractors across Lancaster and South Central Pennsylvania. To ensure we were comparing apples to apples, we asked every contractor the same four essential questions:

1. Will you perform a formal Manual J Load Calculation?
   Why it matters: Sizing a furnace purely based on square footage often results in oversized equipment that short-cycles, wears out prematurely, and creates cold spots.
2. How will you handle venting requirements for a high-efficiency unit?
   Why it matters: Modern 90%+ AFUE furnaces generate acidic condensate and require PVC pipe venting through an exterior wall rather than utilizing an existing masonry chimney.
3. What specific permits and inspections are included in the proposal?
   Why it matters: Gas line connections, electrical work, and exhaust venting require local municipal permits and safety inspections in Pennsylvania.
4. Who handles the utility rebate applications?
   Why it matters: Regional gas utilities (such as UGI, PECO, or Columbia Gas) offer rebates ranging from $300 to $1,500 for qualifying high-efficiency units, but paperwork deadlines are strict.

Comparing the Bids: Beyond the Bottom Line

When the estimates arrived, we created a side-by-side breakdown to look past the total price tag and analyze what was included in each contract.

Contractor Proposal	Equipment Brand & Model	AFUE Rating	Scope / Inclusions	Total Estimate
Option A (Local Independent)	Trane S9V2 (Two-Stage)	96% AFUE	Manual J, PVC venting, custom plenum transition, permit fees, 10-yr parts / 2-yr labor warranty	$6,800
Option B (Regional Franchise)	Carrier Performance 96	96.5% AFUE	Standard swap out, basic PVC venting, 10-yr parts / 1-yr labor warranty	$7,450
Option C (High-End Specialist)	Lennox SL280V / Variable	98% AFUE	Full custom sheet metal, smart thermostat, zoning check, 10-yr parts / 10-yr labor warranty	$9,200

What Tipped the Scale for Us

• Workmanship & Labor Warranty: Equipment warranties come from the manufacturer, but labor warranties come directly from the contractor. Option A offered a strong two-year labor guarantee with an option to extend.
• Custom Sheet Metal Capability: Our old 1990s cabinet size didn't match modern furnace dimensions. Option A took detailed measurements of our supply and return plenums to fabricate custom sheet metal transitions on-site rather than forcing flexible duct adapters.
• Rebates Assistance: Option A offered to submit the UGI utility rebate paperwork directly on our behalf, instantly reducing our net cost by $600.

---

Next Steps for Execution

1. Verify Licensing & Insurance: Confirm contractor licensing on the Pennsylvania Attorney General Home Improvement Contractor (HIC) registry and request proof of liability insurance.
2. Review Payment Terms: Standard terms usually require a 10% to 30% deposit upon booking, with the final balance due only after local inspection sign-off.
3. Lock In Installation Dates: Schedule the work during mild shoulder seasons (early autumn or early spring) to avoid peak winter emergency rush rates.

In Part 3 of this series, we will take you through Installation Day: what to expect during removal, line routing, testing, and final walkthrough.