Furnace replacement cost: quote checklist
Understand the equipment, venting, gas, electrical, duct, permit, testing, and warranty items that shape a furnace replacement quote.
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A furnace proposal is easiest to evaluate when the price is tied to a written scope. The cabinet and efficiency rating matter, but so do venting, gas piping, electrical work, airflow, controls, permits, removal, and safety testing.
The HVAC replacement cost calculator can provide a planning range for a furnace or full central-system project. Use it before collecting bids, then replace assumptions with what each contractor can observe in the home.
Confirm the fuel and project scope
Gas, oil, electric-resistance, and heat-pump heating projects are not interchangeable. Even within a gas-furnace replacement, a like-for-like equipment change differs from a conversion to a condensing furnace that needs new vent and condensate paths.
Check whether the quote includes only the furnace or also the air-conditioning coil, outdoor unit, thermostat, filtration, humidifier, or zoning controls. Ask for indoor and outdoor model numbers when cooling equipment is part of the project.
Capacity still needs a load calculation
The old furnace input rating is not proof that the home needs the same capacity. Insulation, windows, additions, air sealing, and prior oversizing can change the relationship between the old nameplate and the actual load.
ACCA’s Manual J process evaluates the home rather than relying only on square footage. Ask for both input and output capacity: furnace efficiency affects how much delivered heat comes from a given fuel input.
Venting and combustion work can change the price
Fuel-burning equipment must be vented and commissioned correctly. A proposal may need to address chimney condition, liner requirements, sidewall termination, combustion air, condensate disposal, gas pressure, and vent clearances. These conditions cannot be estimated reliably by a web form.
Ask what safety and startup measurements will be documented. Depending on the equipment and local requirements, that may include temperature rise, gas pressure, combustion analysis, draft, carbon monoxide checks, and airflow.
Airflow and ducts are part of furnace performance
A new blower does not fix every duct problem. Return-air restrictions, undersized supplies, closed dampers, dirty coils, and poor filter selection can raise static pressure and affect noise, comfort, and equipment operation.
If a quote includes duct changes, ask the contractor to identify the measured problem and the proposed correction. Separate necessary airflow work from optional accessories so the comparison remains clear.
Compare warranties carefully
Manufacturer warranties usually cover specified parts under stated conditions. They may require registration and may not pay for diagnostic time, travel, refrigerant, shipping, or contractor labor. The installing company’s labor warranty is a separate promise.
Record the term, exclusions, transfer rules, registration responsibility, and who handles a claim. A warranty headline without these details is difficult to value.
Questions to ask before signing
- Which exact model and efficiency rating is proposed?
- How was the heating capacity selected?
- What venting, gas, electrical, duct, drain, and control work is included?
- Who obtains permits and schedules inspection?
- Which startup and safety measurements will be recorded?
- What is excluded or left as an allowance?
For a full-system comparison, also read what changes HVAC replacement cost and the site’s calculation methodology.