In-floor heat question

[Alphacowboy]

I want to install a floor heat mat in a bathroom I am working on, and the problem I am running into is getting power to the bathroom itself. This is on the 2nd floor of a house(basicly 3 floors if you include the basement), basement is finished and the panel is not in the mechanical room. There is no sofets, and no closets lined up from the upstairs to the basement... what to do! There is a whirlpool in the bathroom, and is on a dedicated 20A curcuit. Could I use this curcuit? I know you couldnt probably run the floor heat and tub at the same time (not a heated tub, just a pump) but turning off the floor stat when the tub is used really isnt that big of a deal. The tub is rarely used. The floor stat says that it would use 15A maximum, and requires a 20A curcuit. I know it would be kind of hillbilly, but would putting in a selection switch be ok? Basicly, flip it one way, infloor heat works, the otherway, tub works. Obviously this way it would not overload the curcuit by having them both on by accident.

I really dont want to try and get a wire to the panel, as its going to require sheetrock removal, and I really do not want that mess.

[GilBeQuick]

Is your floor heat 240v or 120v?

[Alphacowboy]

Is your floor heat 240v or 120v?

120v, the tub is also 120v

[nobody1]

can you get to the wires feeding tub easy enough and tie it into a 3- way switch, the re-feed tub and mat?

[Alphacowboy]

The tub control switch (timmer switch) is in the same stud space as the floor control. To be honset, the tub is never used, in 10 years, its been used 3-4 times. That is why I am thinking it wont matter, and was planing on the switch just as a fail safe. 99.999999% of the time, the floor is the main use, not the tub.

[GilBeQuick]

It will work just fine. What you need is either a single pole double throw (SPDT) switch or a single pole changeover switch (SPCO). The difference is that the SPCO will have an off position in the middle and the SPDT will not. The only thing I see that might be an inconvenience to you is when you go to use the tub your memory setting from your floor heat control will be wiped out.