I notice my furnace and electric water heater have switches. Why do they have a switch, is it for convenience or are they required by code. Each of these are on a dedicated breaker and the breaker panel is only 15 feet away. The switch just seems like another thing that can fail.

  • I can't see it being all that useful for a water heater, but a switch on a furnace can be very handy when doing maintenance/repairs, even if the breaker isn't very far away. – manassehkatz Feb 5 at 23:16
  • Is the panel within sight from the furnace and water heater? – ThreePhaseEel Feb 5 at 23:34
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    A switch has a vanishingly small probability of failure, especially one that is infrequently used. Almost certainly the switches are required by code and they are convenient. – Jim Stewart Feb 5 at 23:52
  • No they are not within sight, both in basement but in separate rooms. The furnace was recently replaced and it has a switch. The water heater will be replaced soon and I'd like to get rid of that switch. – Platinum Goose Feb 6 at 0:13
  • Call your local electrical inspection office and find out whether they require a switch for the hot water heater. If they don't require one, then you can take it out, but if they do require one and you have removed it, then you could be liable to replace it in the event of a sale of the property or have legal liability in the event of a shock accident. – Jim Stewart Feb 6 at 4:23

NEC Articles 110.25, 422.31, 422.33, 422.34 and 430.102(A) provide requirements for disconnects used to protect those who might need to service equipment. Basically it requires the following.

  1. It must be with in line of site and less than 50' from the equipment.

  2. The disconnect means must be able to be lockable for hardwired or plug and cord.

  3. Many AHJ have also require the access to the disconnect to be in an unencumbered path from the equipment.

Also as mentioned by Jim Stewart, it is there for safety's sake and it is rare these devices go bad.

Hope this helps.

  • I found this in our my towns code so you are correct. "Each furnace, heat pump, water heater, air conditioning unit and similar equipment shall be provided with dedicated branch circuits. A disconnecting means shall be provided on or immediately near the equipment." – Platinum Goose Feb 6 at 21:10

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