Is it against code to have a 20amp circuit in an exercise room in a basement? Should our builder have known that we would be using exercise equipment and that a 20 amp circuit should have been used? Right now, While using the treadmill, it does smell a little and did shut off last week after using the elevation device. The closest 20 amp circuit is in the other room. Before the basement was remodeled, I used to plug it into a surge protector with a heavy duty extension cord, and it worked just fine. Is this an option?
Thanks for any help.

AH - Sweet Irish, sure you beautify the very green earth you stand on, don't you now.

Now that the blarney is our of the way, I think you are looking at two different issues.

A 20 amp circuit can be anywhere you want it to be. However, if you are using a previous circuit that was designed for a 15 amp circuit you may have an active fire hazard.

A 15 amp circuit can run on a 14/2 AWG cable or a 12/2 AWG cable. As long as the breaker is a 15 amp breaker.

A 20 amp circuit requires a 12/2 AWG cable or larger depending on the circumstances.

What you cannot do, is to take a 14/3 AWG cable and put a 20 amp circuit breaker on it. The 14 AWG conductors are not made for that heat.

Low amperage will not cause the exercise unit to smell. Unless you are smelling a motor or some other electrical component dying out on you.

As to the amperage, there should be an electrical plate on the front of the unit that gives the required amperage.

Can you tell us what that is, please.