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Plug & Cord for Boiler

There have been a few discussions about the addition of a plug and cord to a boiler (or furnace) to allow for easy connection to emergency power (generator or battery/inverter). There was much worry about safety, and of course, code compliance. This is what I did (see photo):

Single oulet dedicated 15 A circuit.
14/3 SJOW cord about 2 ft long.
Kept service switch and MC cable pigtail to boiler.


  • Zman
    Zman Member Posts: 7,572
    I think that is a practical solution. I don't think anyone had a safety concern with that approach. I just doesn't happen to meet electrical code.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • kcopp
    kcopp Member Posts: 4,438
    I do this w/ pretty much all my gas wall hung units.
    The primary reason I do it is to install a surge suppressor in-line to give a measure of protection to the PCB and electronics.
  • NY_Rob
    NY_Rob Member Posts: 1,370
    That would also work for people who plug their boilers (mod-cons) into a UPS. Plug the male connector into the UPS Battery/Surge outlet and you still have the ability to power down the boiler via the Emergency cutoff switch.
  • Bio
    Bio Member Posts: 278
    edited March 2018
    JUGHNE Member Posts: 11,074
    For those going with the cord, I used to get 3' long14-3 flat gray power supply cords for garbage disposals. The advantage was that the male end was a molded 90 degree angle cap. Makes for a more compact install, FWIW
  • HomerJSmith
    HomerJSmith Member Posts: 2,467
    kcopp--I have install many whole house surge protectors and surge capacitors, but, on mod/cons, regardless of a whole house surge protector, I always use a computer grade surge protector and power everything off of that. That means zone control boxes, too.

    As I recall, the NEC requires a disconnect and a plug and cord qualifies as well as a breaker in a panel in sight of the appliance.
    The switch is just more convenient.
  • ratio
    ratio Member Posts: 3,649
    IIRC the Code also requires permanent equipment to be permanently connected, so not supposed to be cord and plug connected. The AHJ will tell you the correct interpretation for your area.

    Also, a lockable breaker lockout is a Code acceptable means of disconnect, but not for refrigeration equipment, which must still be within sight.