Most service contracts put the promises near the front and the limits further back. The exclusions page is where the limits are listed, and it is the page that tells you what the contract will not do. Before you compare two plans or decide whether to renew one, find that page and read it all the way through.
What an exclusion is
An exclusion is a stated item, condition, or situation that the contract does not include. It can be a category of equipment, a type of repair, a condition that existed before the contract started, or a result of how the system was used or cared for. Exclusions are normal in service agreements. They are not a sign that a contract is poor. They are the boundary of what the contract covers, and you need to know where that boundary sits.
Categories to look for
Read for the usual kinds of exclusion. Look for wear items that the contract treats as the owner's responsibility. Look for damage attributed to missed upkeep, unapproved modifications, or work done by someone other than the provider the contract names. Look for language about code upgrades, permits, and site work that the contract may leave out. Look for any clause that carves out older equipment, pre-existing conditions, or systems that were not inspected at the start. Mark each one, and then ask what each means for the specific system in your house.
Read the exclusions against the definitions
Exclusions often lean on defined terms. A phrase like a covered part or an authorized provider can change the meaning of the exclusion around it. Read the exclusions with the definitions section open beside you, and write down any term you cannot explain in your own words.
Questions to ask before you sign
Ask the provider to show you where each exclusion applies to the equipment you own. Ask which exclusions are most often relevant to systems of your age, and ask how the provider decides whether a repair falls inside or outside the contract. Ask for the answer in writing. Ask what your upkeep obligations are under the contract, and what records you are expected to keep. Compare the answers across any plans you are considering.
Using the published figures alongside the contract
The contract tells you what it covers. The service life figures on this site tell you how long each system typically lasts, which is a separate question. Use both. The appliance service life ranking and the individual system guides give the published planning figures. A plan that is silent on the system you are about to plan for is worth knowing about before you commit.