A useful HVAC replacement quote should tell you what system is proposed, why it fits the home, what work is included, how the installation will be checked, and which terms will appear in writing.
Before comparing totals, make sure the proposals describe the same job. A lower number can simply mean that one bid excludes work another includes—or leaves an important decision unresolved.
Make the scope comparable first
Create one column for each proposal and mark every relevant item:
- Included — part of the quoted total;
- Excluded — not part of the job;
- Conditional — may be added after an inspection or another event;
- Unclear — the proposal does not say; or
- Not applicable — not part of your system or project.
Treat “unclear” as a question to resolve in writing before comparing the proposals.
1. What exact system is being proposed?
Look for the model numbers or other clear identities of the indoor and outdoor equipment, the proposed capacity, and the stated efficiency ratings. If the proposal refers to a matched system, ask for the AHRI reference or certificate that identifies that specific combination.
Then ask how the capacity was chosen. A replacement should not be sized only by copying the old unit or using a rule of thumb. The proposal should identify the load-calculation method and the home details used, such as size, insulation, windows, and other relevant characteristics.
You do not need to check the contractor’s engineering. You are looking for evidence that both bids start with the same understanding of the house.
2. What work is included—and what is not?
The exact scope varies by home. For each proposal, clarify the status of:
| Scope question | Bid A | Bid B | Bid C |
|---|---|---|---|
| Indoor and outdoor equipment | |||
| Duct inspection, testing, sealing, or repair | |||
| Refrigerant line work | |||
| Electrical, gas, venting, and drain work, where applicable | |||
| Thermostat or controls | |||
| Required permits and inspections—and who handles them | |||
| Old-equipment removal and cleanup | |||
| Any work described as conditional |
The rows expose assumptions; they are not a list of items every project must include. One contractor, for example, may include duct repairs while another has priced only the equipment swap.
3. How will the installation be checked and handed over?
Ask what the installer will verify before calling the job complete. Depending on the system and scope, that may include airflow, refrigerant charge, controls, startup operation, or duct testing. The proposal should say which checks apply and what record, if any, you will receive.
Also clarify the closeout package:
- equipment manuals and model/serial information;
- the load-calculation result or design record;
- an AHRI certificate or reference for matched equipment, when applicable;
- startup or test records promised by the contractor; and
- written warranty terms.
An AHRI certificate documents rated performance for a particular equipment combination. Correct installation still depends on the work at the home.
4. What will the written agreement say?
A detailed quote helps you compare bids, but it may not be the final contract. Before signing, make sure the written agreement identifies the contractor, the planned work and materials, estimated timing, price and payment terms, warranty promises, and how changes will be approved. Resolve blank or vague fields rather than relying on a conversation.
If you signed at home, you likely have three days to cancel
There is a federal rule here, and it is worth knowing before you sign. Under the FTC's Cooling-Off Rule, when a sale is made at your home — or at your workplace, or at a seller's temporary location — the right to cancel for a full refund lasts until midnight of the third business day after the sale. HVAC replacement is often sold that way: in the living room, the same afternoon as the assessment.
The exceptions are narrower than they sound, and two of them are worth stating precisely, because assuming they apply is how people give up a right they actually have.
A hot day is not automatically an "emergency". The rule's emergency exclusion is not satisfied by urgency alone. It requires that you initiated the contact, that the purchase meets a bona fide immediate personal emergency, and that you gave the seller a separate dated statement, in your own handwriting and signed, describing the emergency and expressly waiving your right to cancel. If you did not handwrite and sign such a statement, that exclusion does not apply to your sale.
A repair visit does not remove your rights from a replacement sale. If you called someone out to repair your system, that requested repair can fall outside the rule. But the regulation is explicit that if the seller then offers additional goods or services — anything beyond the replacement parts necessarily used in the repair itself — those additional goods and services are not covered by that exclusion. A new system sold to you during a repair visit is an additional sale, and the cancellation right generally applies to it.
Other exclusions are more mechanical: sales under $25 at your home or under $130 at a temporary location, purchases made after you completed negotiations during your own visit to the seller's permanent business location, sales conducted and consummated entirely by mail or telephone, and goods or services not mainly for personal, family or household use.
Federal law is a floor, not the whole picture. License, insurance, permit, contract, and down-payment rules vary by state and locality, and state or local law may provide cancellation rights beyond the federal three days. Check the relevant state or local authority as well. Ask the contractor to state the cancellation terms in writing before you sign — and if you are told you have no right to cancel an at-home sale, check that against the rule itself rather than taking it on trust. For your specific contract, rely on the FTC's guidance or a qualified adviser rather than a general article.
Five questions when two proposals differ
- What does one proposal include that the other excludes or leaves conditional?
- Why do the proposed capacities differ, and what home information supports each one?
- Which installation checks and records will each contractor provide?
- Who is responsible for permits, inspections, qualified trade work, and equipment removal?
- Which verbal promises need to be added to the written agreement?
Large differences deserve an explanation. Once the scopes are explicit, you can compare the work being offered rather than three totals that may describe three different projects.