I bought a 220 Softtub. It comes with a cord about 15 long with GFCI. It's about 3 feet short of the outlet outside. 110 - just plug in and play. Would it be OK to add a 3 foot extension cord with same guage wire to plug in to outside outlet? Any other suggestions?
Thanks in advance.
Kelsey

The proper way to plug in a 120V tub is to not add an extension cord, but to install a dedicated outlet in proper reach of the tub. The NEC actually limits the length of a cord from a spa, but I don't recall off hand what that distance is. Adding 3 feet could be in violation. But if you do decide to go this route, don't use an extension cord, but replace the entire cord so there are no breaks (plugs) in it from the spa to the outlet