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boiler requires separate circuit?

AlexRAlexR Member Posts: 61
I'm in Massachusetts.  Is there a code requirement that my boiler be on a dedicated circuit?  There's a switch on the side of the boiler that shuts off power power.

Reason for asking is that I'd like a dedicated circuit for another piece of equipment in the basement of our 2 family.  I'd like to put the boiler + basement lights on one circuit and repurpose the boiler's circuit for the new appliance (actually, an outlet for charging a plugin-hybrid car).  We're on the second floor, so getting a new wire from our panel to the basement may be hard.  The boiler system (gas control, damper, lwco, 2 taco relays, 2 taco 007-f5 circulator pumps) only draws a few amps (under 5, by my calculation) so it seems like having it on the same circuit as 4 fluorescent bulbs should be fine.



  • icesailoricesailor Member Posts: 7,265
    Separate Circuit:

    It has always been my understanding that boilers must be on their own properly sized circuits.

    That if you have a boiler in an open cellar with no partitions, the remote safety switch must be located OUTSIDEW the cellar and not inside the top of the cellar door.

    Furthermore, why would you want the boiler on the same circuit as the lights? If the circuit trips because of the boiler, you have no lights.

    I have never seen a Licensed Massachusetts electrician wire a boiler on a shared lighting circuit.

    Massachusetts oil burner technicians are allowed to wire a replacement boiler and controls on an existing system. Not from scratch. But it must be its own circuit

    How many amps is that car charger?
  • AlexRAlexR Member Posts: 61

    The charger wants a 15A circuit.  I suspect it runs relatively close to capacity for that circuit.  60W of CFLs would probably be OK, but seems safer on the boiler circuit.

    Your point about no lights if the circuit trips is valid, though we do have flashlights.  :)

    More seriously, there's an outlet too that could be used for a lamp/floodlight if it were on the same circuit as the charger (and that'd be OK, since I know not to use it while the car's charging).

    The basement is partitioned and it'd be easy to install another shutoff switch for the boiler outside that partition if that's what's needed for code compliance.
  • pugdadpugdad Member Posts: 20
    mass code

    Mass code does state separate branch circuit for oil burners
  • SWEISWEI Member Posts: 7,356

    would work around this.  What kind of wiring feeds the two circuits you have now? 
  • AlexRAlexR Member Posts: 61
    gas burner

    It's a gas burner, not oil (Burnham IN-5, no power vent and no electronic ignition).

    Both circuits are 14/2 romex right now, so not sure if subpanel is feasible.  Also, if I understand correctly, not proper to just up the breaker on the panel since 20A requires 12AWG wiring.


    There are other options, like adding a new master panel that connects to the meter and feeds the current panel.  But I'd rather avoid the expense if I can do so and stay within code.
  • SWEISWEI Member Posts: 7,356
    14/2 NMS

    Not much wiggle room there for sure.  How does the power come into your 2nd floor unit?  Is this a multi-tenant building?
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