Published by Comfy Castle Heating and Air
License # AEC01319 / LIC00252624
Last updated 2026-10-02
4 minute read
A furnace replacement proposal should explain the equipment, related installation work and responsibility for permits and inspections. Before scheduling, confirm the property's jurisdiction and ask what documentation you will receive when the project and inspection process are complete.
What information should you bring to the estimate?
Have your property address, current furnace model information and the reason for replacement ready. Note comfort problems such as uneven rooms, unusual cycling or repeated repairs. Describe whether the furnace will stay in the same place and whether other equipment will be replaced at the same time. You do not need to diagnose the system yourself.
Keep the household's needs separate from the proposed equipment specifications. Tell the installer about a finished basement, planned addition or rooms that never reach the thermostat setting. Ask how those facts affect the recommendation rather than assuming the old furnace's label defines the appropriate replacement.
Which permit questions belong in the proposal?
Ask which building department has authority, which permits are expected and who will apply. Denver publishes a residential mechanical quick-permit path that includes forced-air heating, subject to eligibility. Littleton's guidance includes mechanical-system replacement in its permit requirements. Use the relevant official page for your property instead of applying another city's process.
Request a written allocation of responsibility: application, supporting documents, inspection scheduling, access to the property and any required corrections. Ask how permit fees are handled without assuming a standard metro-wide charge. If the proposal excludes part of the process, clarify who will complete it before accepting the work.
What installation details deserve a clear explanation?
Ask the installer to describe the planned venting, combustion-air arrangements, gas connection, electrical connection, thermostat and any duct changes. If the proposed system needs a condensate drain, ask where that work is included. These are questions for the professional designing the installation, not instructions for a homeowner to modify the equipment.
A change in furnace type, location or associated equipment may change the scope. Ask how existing connections will be evaluated against the proposed equipment and applicable requirements. Avoid accepting an unexplained statement that every old component can be reused, or assuming every component must be replaced without an assessment.
What can go wrong between installation and sign-off?
The most preventable gaps are unclear responsibilities and missing records: nobody knows who requested the inspection, a return visit is not scheduled, or the homeowner receives an invoice without the permit number. Ask for the sequence in advance and keep the installer's contact information with the project file.
Greenwood Village explains that inspectors can require corrections when work does not meet applicable standards. If that happens, request an explanation of the finding and the next step. An inspection correction is something to resolve and document; a promise that the furnace runs is not the same as a completed inspection record.
What should you receive at project completion?
Ask for the final invoice, installed model information, warranty and maintenance instructions, startup information provided by the installer, and the permit and final inspection record where required. Confirm that the paperwork describes the equipment actually installed. Keep a copy somewhere you can retrieve when arranging future service.
Still deciding whether to replace? Start with the furnace repair-versus-replace guide and obtain a diagnosis before committing to a new system. This checklist is general educational guidance, not legal advice or approval of a particular installation. Confirm current requirements with your property's building department and revisit them if the scope changes. Gas and electrical work belong with qualified professionals.
Frequently Asked Questions
- Can I assume a replacement needs the same paperwork as the last furnace?
- No. Ask about the current requirements for the proposed work, even when the new furnace will occupy the same space.
- Does this checklist guarantee inspection approval?
- No. The responsible department evaluates the actual work. The checklist helps you agree on responsibilities and keep the resulting records.
- What if electrical work is handled by someone else?
- Have the proposal identify that work and its responsible trade, including any separate permit or inspection requirements determined for the project.
Sources and further reading
This guide provides general homeowner information. Equipment instructions and an assessment of your home determine the work required. For help in the North and South Denver Metro Area, contact Comfy Castle Heating and Air.