A home warranty can protect homeowners from expensive out-of-pocket repairs by helping cover the cost of replacing or repairing some major systems and appliances. But you may be surprised to learn what's actually covered — and what isn't — with a typical home warranty.

What does a typical home warranty plan cover?

When buying a home warranty, your contract is the best place to find out what exactly is covered and if there are any exceptions. Different types of warranty plans can cover your home's major systems, major appliances or both. This coverage typically includes:

Major systems

• Heating.

• Cooling.

• Plumbing.

• Electrical.

Major appliances

• Built-in microwave.

• Range/stove/cooktop.

• Oven.

• Dishwasher.

• Garbage disposal.

• Garage door opener.

Depending on the company, some home warranties can also include additional coverage for these appliances:

• Refrigerator.

• Washer.

• Dryer.

• Water softener.

Home warranty plans typically cover most parts and components for "normal wear and tear," which is the gradual failure that happens over time with everyday usage.

In addition, home warranty plans usually have a coverage limit, which puts a cap on how much the company will pay to repair or replace a particular item. For example, let's say your oven fails: Your policy might have a limit of $500 to repair or replace it. If the cost is greater than what's indicated in your contract, you will pay the difference.

» MORE: What is a home warranty, and how does it work?

Add-on coverage

For an extra cost, you may be able to purchase coverage for additional items that aren't covered by a typical home warranty or extend coverage. Including:

• Pool and spa.

• Well pump.

• Septic pump.

• Roof (leak repairs).

• Electronics (like TVs and computers).

• Guesthouse or rental unit.

What doesn't a home warranty cover?

While a home warranty plan may help pay to repair or replace a specific system or appliance, the warranty doesn't necessarily cover everything that can go wrong with that item. Every provider's contract contains exceptions and exclusions to their coverage.

For example, your plan's contract may cover plumbing leaks, but blockages due to roots located outside of the home's structure may be excluded.

Also, note that an appliance repair or replacement (say, your stove or toilet) will typically not guarantee parts or equipment of the same brand, color, or size. So while your appliances might get fixed, you could end up having a mismatched kitchen or bathroom.

Here are some things home warranties typically don't cover (note that coverage varies depending on the provider, and you should check your contract for specifics):

• Areas outside the main part of the house, such as underground pipes or sewer lines, unless you've specifically added them into your coverage (like a pool or septic tank).

• Homes larger than 5,000 square feet (you'll likely have to pay more for this coverage).

• Pre-existing conditions or problems that were discovered before you purchased the warranty. This can include any negative items found during a home inspection or indicated in the seller's disclosure.

• Sprinkler systems and outdoor plumbing, such as faucets.

• Repair of structural parts of a new construction or remodeled home, like walls, floors and plumbing (which would be covered by a builder warranty).

• Systems and appliances that have been improperly maintained, repaired, modified or installed.

• Recalled items or any systems or appliances covered under another warranty (like from a manufacturer).

• Properties that are used as a commercial business, such as a bed-and-breakfast or day care.

• Coverage for more than one of the same appliance or system — you'd need to pay extra to cover an additional refrigerator or dishwasher, for example.

• Cosmetic damages, such as dents or scratches, and damages from pests like termites.

Exclusions covered by your homeowners insurance

While your home warranty may cover a leaking toilet, for coverage of secondary damages — like a buckled floor after your faulty toilet leaks — you'd need to rely on your homeowners insurance coverage.

This is because a home warranty is only meant to cover typical failures of systems and appliances that occur over time (remember, "wear and tear"). That means a home warranty doesn't cover unexpected events, e.g., any damage that might arise as a result of those appliance failures. You'd also turn to homeowners insurance in the event of damages from fire, theft, hail, wind or electrical issues caused by power surges/failures and lightning strikes.

And the same rationale applies to structural parts of your home like doors, walls and windows. These items are not expected to falter in the same way systems and appliances are subject to normal wear and tear, so they're not covered under a home warranty.