I had a hot tub which we down sized. The old tub had a 220 dedicated GFCI breaker subpanel. The new tub requires 110. Is there a way to easily down size?

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    For the best answer we would need to know how many wires are going to the subpanel and what size they are and the power requirements for the new hot tub (amperage), but this should be possible and pretty easy. In other words, we need a lot more detail. – JPhi1618 Feb 5 '20 at 18:48
  • Could you post details or a picture of the subpanel and circuit requirements for the hot tub. It might be as easy as buying a 120v gfci breaker. – NoSparksPlease Feb 5 '20 at 18:56
  • Your heater will take a long time to heat the water. – JACK Feb 5 '20 at 19:14
  • Unless the tub holds half as much water... ;-) – JRaef Feb 5 '20 at 19:37
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    @JRaef but 1/4 the wattage. – JACK Feb 5 '20 at 20:45

The answer is it will be easy to change fro 240 to 120v. Your 240v feed uses 2 hot’ and a ground at a minimum possibly a neutral. Moving the wires in the main panel will be need to install a 120v 15 or 20a receptacle Remove the 240 v GFCI and install a single pole GFCI. Put the black on the GFCI tie the neutral pigtail to the neutral buss and the white to the neutral point on the breaker, ground to the grounding buss if a main panel the neutral buss can also be used, if there is a red wire put a wire nut on it.

Depending on the size of the original feeder you may need to pigtail to a #12 wire on the breaker (and at the new receptacle) you may need a new box or mud ring at the tub location to mount your receptacle and pigtails.

If the box is in the weather a bell box or weather tight box and an extreme use cover or In use cover for the outlet.

I suggested a #12 wire for the new circuit because the few small tubs I have installed receptacles for were 15 & 1 was a 20 amp. If it happens to be 30 amp 120v (I have not seen for a hot tub but possible that would require a #10 awg wire. For the pig tails if needed.


I agree with Ed Beal. Converting a 120/240V circuit to 120-only is very easy; you'll just be tapping neutral and one of the hots, instead of both hots. You will need to downsize the breaker.

Where I diverge from Ed is that I would not downsize a $50 or $100 GFCI breaker, but would instead look for a way to use a $5 plain breaker, either downstream, or upstream of the GFCI breaker.

  • For instance, many "hot tub subpanels" have spaces for accessory breakers. Use one of those to power the new hot tub.
  • Or, presuming the hot tub subpanel contains the GFCI, and does not contain any accessory breaker spaces, then change the feed/supply breaker in the main panel to 15A or 20A or whatever is correct for the new tub. This is perfectly legit: the main panel breaker provides overcurrent protection, and the 50A GFCI breaker provides local disconnect as well as providing GFCI protection. This is the same strategy as installing a large 30-space subpanel in an outbuilding, where it's supplied with a 60A breaker but the subpanel has a 200A main breaker as a disconnect, because that's how large panels are made.

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