Actually that's not the case for other issuers.

Chase's exclusion policy for example are as follows, no mention of permanent addition or fixtures: ( Quoting benefits guide for the CSP )

What items are not covered?
• Boats, automobiles, aircraft, and any other motorized vehicles and their motors, equipment, or accessories, including trailers and other items that can be towed by or attached to any motorized vehicle
• Any costs other than those specifically covered under the terms of the original manufacturer- written U.S. repair warranty, as supplied by the original manufacturer, or other eligible warranty
• Items purchased for resale, professional, or commercial use
• Rented or leased items or items purchased on an installment plan and for which the entire purchase price was not paid in full at the time of the occurrence
• Computer software
• Medical equipment
• Used or pre-owned items

CitiCard's :


WHAT’S NOT COVERED
Your coverage doesn’t apply to the following items:
Purchases
■ Boats, cars, aircraft or any other motorized land, air or water
vehicles or their permanently attached parts.
■ Items that are rented, leased or purchased on an installment plan
and not paid in full when the breakdown occurs.
■ Any additional service contract or extended warranty attached to the
purchase.
■ Services (such as product installation, repairs, maintenance or
diagnostics) that aren’t covered under the original manufacturer’s
warranty.
■ Items purchased for resale, or for professional or commercial use.
■ Used, antique or pre-owned items.
■ Medical equipment.
■ Land, buildings or permanently installed fi xtures, such as windows,
wallpaper or wall-to-wall carpeting.

That being said, the retailer's service agreements for appliances may be easier to claim compare to credit card coverage ( which may require getting a quote to be submitted for approval first before service can be approved )