hot to cold and then back to hot,, about evert 10 to 15 seconds it changes,, your takin a hot shower and cold water hits you all of a suden, then back to hot,,, it has a 2 handle faucet,
#1
I am going to guess that you have a temp and or pressure shower valve that is not working right...that would be where I would start looking for a problem...unless you are having the problem else where in the home...