This guide is general. It does not read any particular contract, and it does not describe what any named company's contract covers or requires. It explains the steps a home unit usually goes through when it is installed under a service contract, and the paper each step should leave behind.
Before the crew arrives
Find the contract's install section before the delivery day. Many service contracts say who may install the unit, whether the installer must follow the maker's written instructions, and whether a permit or inspection is needed. Some contracts make the installation terms a condition of coverage. Others say nothing. Look for the words install, installer, placement, and inspection, and mark each one that appears.
Ask the seller in writing who the installer is, whether that person is the seller's own staff or a subcontractor, and whether the install is covered by the seller or by a separate party. Those are two different answers, and the paper should name which one applies.
Check whether a local permit is needed for the work. The office that issues building or electrical permits where the unit will go is the source for that answer, not the seller. Keep the permit number when one is issued.
On the day
Stand where you can see the work. Confirm that the unit that arrives is the unit on the order. Write down the model and serial numbers from the data plate before the crew moves the unit, and photograph the plate so the image shows all of the text. The serial number is the link that ties the contract to the unit, so a wrong or unreadable number is a problem to fix on the day, not later.
Note the placement. Record the room, the wall or floor position, the clearances the maker's instructions give, and any connections made to water, gas, power, or a vent. If the crew changes the placement from the plan, ask for the reason and write it down with the time.
Ask the crew to show you the test or start-up step. Note what was tested, what the result was, and whether the crew signed off. Do not sign a completion page that says more than the test showed.
What to file after
Ask for the installation invoice or work order. It should name the unit by model and serial, give the install date, name the installer, and list the work that was done. Compare it against your photographs and notes. A mismatch is easier to fix while the crew can still be reached.
Ask for the permit closeout or inspection record if a permit applied. Ask for the maker's installation sheet and any product registration card the maker asks you to return, and keep a copy of what you returned and how you sent it.
Put all of these in one folder with the signed contract, the sales page, and your notes. Name the folder with the unit and the install date so the record can be found without searching.
What this guide does not cover
This guide does not say when coverage starts. That is set by the contract and is often tied to a waiting period or to the install date, so read the start-of-coverage terms separately. For the rules that apply in each state, use the state pages on this site, which name the statute, the regulator, and the as-of date of each roster.