I have hotwater through out the hourse except in my Master Bath tub, the shower unit is separate, I checked all the sinks both in the master the second and third bath room the bath and tub in the second as well as the kitchen all work great just my master bath does not have hot water. Need some help seems sort of weird I am thinking frozen pipe it is not that cold and other areas would have been effected if that were the case.

If there is water in master bath sink and not tub. I would think and goes with out saying
Valve was shut off
The pipe froze to tub and not sink
Bathtub faucet bad.
Did you notice any changes in the bath faucet?
And what is "not that cold out"?
I hear that a lot and its how a person feels what is was the outside Temp in the last 24 hrs and was it windy?
More info could help before throwing suggestions Thank You !
Happy Holidays!