When a repair is done, two things may be promised: the part and the work of installing it. They are often promised by different parties. A manufacturer may stand behind a part for a stated period, while the person who fitted it stands behind the labor for a different period or not at all. If you do the job yourself, the labor promise disappears and only the part promise remains, if the part has one.
Sort the job into its two halves
Before you decide whether to hire, write down the part being replaced and the labor needed to fit it. Then find each promise. Look on the packaging, the invoice, and the paper that came with the item for the part promise. Look in the work order or agreement for the labor promise. Note the start point for each, such as the date of purchase or the date of installation, and note the event that would end it.
What a service contract can change
A service contract may cover labor for certain repairs even when the manufacturer's part promise has ended. It may also exclude labor on parts that a manufacturer covers. Read the contract's terms for labor, and do not assume that a part promise carries labor with it. Ask whether the contract requires that the repair be done by a particular kind of shop, and whether a repair you perform yourself is still eligible under it.
Questions to ask before you choose
Ask the installer whether the labor is warranted, for how long, and in writing. Ask the part's maker whether the promise depends on who installed it. Ask the contract seller whether a repair you do yourself counts toward the contract's terms, and whether it can affect a later claim. Ask what evidence you should keep, such as the receipt for the part and a note of the date and the work done.
What this guide does not do
This guide explains how part and labor promises usually divide. It does not say what a particular manufacturer or contract covers, and it gives no advice on performing repairs. Where a repair involves a trade that a state reserves to licensed workers, the state pages on this site list the rules and the roster where one is published. The contract and the manufacturer's paper control the terms.