Originally Posted by
dan orourke
Builder said this was okay to use the electrical cable for the water heater. I said no, because all manufactures say no. I'm curious, though, is there a code reference and can also use to defend my position?
From the NEC. (bold and underlining are mine)
- 400.7
Uses Permitted.
- - (A) Uses. Flexible cords and cables
shall be used only for the following:
- - - (1) Pendants
- - - (2) Wiring of luminaires (fixtures)
- - - (3) Connection of portable lamps, portable and mobile signs, or appliances
- - - (4) Elevator cables
- - - (5) Wiring of cranes and hoists
- - - (6) Connection of utilization equipment to facilitate frequent interchange
- - - (7) Prevention of the transmission of noise or vibration
- - - (8)
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 (Jerry's note: This does not apply as water heaters are fixed in place and are NOT "specifically designed to permit ready removal - for any reason.)
- - - (9) Data processing cables as permitted by 645.5
- - - (10) Connection of moving parts
- - - (11) Temporary wiring as permitted in 527.4(B) and 527.4(C)
- - (B) Attachment Plugs. Where used as permitted in 400.7(A)(3), (A)(6), and (A)(8), each flexible cord shall be equipped with an attachment plug and shall be energized from a receptacle outlet.
- - - Exception: As permitted in 368.8.
- 400.8
Uses Not Permitted.
- -
Unless specifically permitted in 400.7, flexible cords and cables
shall not be used for the following:
- - - (1)
As a substitute for the fixed wiring of a structure
- - - (2) Where run through holes in walls, structural ceilings, suspended ceilings, dropped ceilings, or floors
- - - (3) Where run through doorways, windows, or similar openings
- - - (4) Where attached to building surfaces
- - - - Exception: Flexible cord and cable shall be permitted to be attached to building surfaces in accordance with the provisions of 368.8.
- - - (5) Where concealed by walls, floors, or ceilings or located above suspended or dropped ceilings
- - - (6) Where installed in raceways, except as otherwise permitted in this Code
The only item in "Uses Permitted" which is even close to applying is the following, and it *specifically* excludes appliances installed in the manner in which water heater are installed.
- 400.7
Uses Permitted.
- - (A) Uses. Flexible cords and cables
shall be used only for the following:
- - - (8)
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 
