There are spas made specifically for 110v operation. These plug and play type spas usually ship with their own GFCI protected power cord, so they just plug into a standard power outlet without needing the services of an electrician most of the time. Many online sources mistakenly say there are 110 volt hot tubs that are different from 120 volt hot tubs. This is not the case with some of the 110/220 convertible hot tubs which you can operate at either 110v or 220v.
Here are some highlights of the differences between operating a spa at 110 volts and at 220 volts in North America.
To install a 220-230 volt hot tub usually requires the services of a licensed electrician to install the circuit breakers, proper gauge wiring from the main electrical panel to the junction box. In addition an outdoor GFCI panel with manual shutoff/disconnect is required in most communities so that also needs to be bought and connected along with running wire and conduit to the actual hot tub and hooking it up. Wiring the GFCI can be a little tricky for electricians that are not familiar with hot tubs since most 230 volt hot tub installations require a 4 wire installation instead of just 3. A wiring diagram can be found in the hot tub owner’s manual and also as a download from Hot Tub Outpost.
The cost of the electrician, wiring, breaker, GFCI, and supplies can cost many hundreds of dollars to even a thousand dollars or more, so eliminating that cost with a 110v spa makes the procurement cost lower.
Although a hot tub is not typically moved around, the 110v version allows it to be easily relocated to another area and another exterior wall plug. With a 230v hot tub, the installation and wiring is fixed and cannot be moved to a different location without calling the electrician back out for some major rewiring.
This is the main payoff for having a 230v hot tub is that the heater can operate while the jet pump(s) are running and the heater can also be more powerful. 110v spas are usually limited to a 1kw heater and are also set to turn off if the pump is turned on high speed, thus keeping the current under the maximum that you can operate on a standard 15A or 20A household power outlet.
A 230 volt hot tub will be able to operate with a 3kw, 4kw or even 5kw electrical flow through heater, so the water heats faster and heats even during use.
Things that Remain the Same
Whether the spa operates at 110v or 220v, some things remain the same. The construction of the spa is typically made of the same materials, the power of the jets is also about the same because although plug and play models may have a less powerful pump (1 1/2hp instead of 3,4 or 5hp), there are also less jets on the line, so the flow rate is kept similar to the flow rate coming out of the larger spas, only the larger ones would have more jets on a single pump. The manufacturer usually adjusts the number of jets per pump to achieve a consistent flow rate.
Both 110v and 220v hot tubs will maintain temperature up to 104 degrees F if the spa is properly covered. The 110v hot tub may heat more often, but use less power when doing so.
You may have fewer jets since the pump is less powerful, but the actual massage/flow rate is more dependent on gallons per minute of water flowing from the jet rather than the actual pump size and operating voltage. The spa may be somewhat smaller so there is less water to heat, so that the 1kw heater found in the 110v spa can keep up with the heating task.
Typically, the 110 volt hot tub will cost less, have less jets, be a mid-size unit, not require an electrician for installation and is portable. The 220 volt hot tub will have a more powerful heater and typically more jets and a larger amount of water/room. The convertible 110 volt units found at Hot Tub Outpost allow you to use them as 110v plug and play hot tubs, but decide later if you want an electrician to come out and setup the external wiring, GFCI and breaker. Then it will take the electrician less than a minute to convert the spa pack from 110v to 220v which automatically turns the same built-in heater from a 1kw to a 4kw heater and allows the pump to operate on high speed even when the spa is heating.
See our other article on how to convert a convertible 110v spa to a 220v spa.