AskCodeMan

Specifically - a water heater. In areas where earthquake straps are not typically enforced, would a vertically installed tank-style water heater be considered a fixed appliance?

There are two types of appliances:

A) Portable appliances

B) Fixed or stationary appliances (appliances which are "non-portable appliances")

Examples of portable appliances are appliances which are self-contained and can be moved/relocated from place to place. Portable electric appliances will thus come with, and be listed and labeled for use with, a cord and plug ("flexible cord" per the NEC).

Thus, for portable electric appliances (examples are: cord and plug connected fans; cord and plug connected space heaters; cord and plug connected space/room air conditioning units (such as window units and standalone units with discharge air ducts to the exterior); cord and plug connected lamps; and the like).

The NEC, in Article 400, covers flexible cords and cables.

In 400.7 Uses Permitted, it addresses uses for which flexible cords and cables are allowed.

400.7(A)(3) states "Connection of portable luminaires, portable and mobile signs, or appliances." If the appliance is a 'portable appliance', a flexible cord and plug may be used.

400.7(A)(8) states "Appliances where the fastening means and mechanical connections are specifically designed to permit ready removal for maintenance and repair, and the appliance is intended or identified for flexible cord connection." If the appliance is not a 'portable appliance', a flexible cord and plug may be used IF ... IF (underlining and bold are mine) "Appliances where the fastening means and mechanical connections are specifically designed to permit ready removal for maintenance and repair, and the appliance is intended or identified for flexible cord connection."

If the appliance is listed and labeled as a portable appliance and is portable (additional examples of portable appliances are: countertop microwave oven with cord and plug, coffee maker with cord and plug, toaster with cord and plug, etc), then it is a "portable appliance"; however, if such appliance is secured in place and is no longer 'portable', then it becomes a non-portable appliance (which is a fixed or stationary appliance).

A water heater is connected to the plumbing system and is therefore not a "portable" appliance, it is a "fixed or stationary appliance".

While the codes do not define "portable appliance", there are some helpful ICC definitions:

From the IMC: (bold is mine)
- Portable Fuel Cell Appliance. A fuel cell generator of electricity this is not fixed in place. A portable fuel cell appliance utilizes a cord and plug connection to a grid-isolated load and has an integral fuel supply.
- Stationary Fuel Cell Power Plant. A self-contained package or factory-matched packages that constitutes an automatically operated assembly of integrated systems for generating useful electrical energy and recoverable thermal energy that is permanently connected and fixed in place.

Hopefully that helps define what a 'portable appliance' is, and what is not portable, i.e., is a 'fixed or stationary appliance'.

A water heater, which is fixed in place (attached to the structure and/or attached to the plumbing system) is a fixed or stationary appliance. No flexible cords and plugs allowed. I'm not sure if that was part of the reason for your question or not, but it is 'all to common' to find water heaters which are cord and plug connected, even though there are no cords and plugs rated for that use, and the water heaters are not listed or identified for use with flexible cords and plugs. The same applies to furnaces and air handler units - all to common to find the cord and plug connected and they are not listed for such.