When I turn on the outside hose faucet I get hot water from my cold faucets and cold water from my hot faucets until I turn the hose off. It happens in all my bathrooms, first and second floors ( 5 baths ) and also in my laundry room washer on second floor (which was just put in this spring) Problem however has occurred before laundry room put in. It definitely only happens when I put the outside faucet on. This outside cold faucet was added on 20 years ago and plumber connected it from the cold faucet line above above my 3 basement laundry tubs in basement. These two old lines directly above the 3 tubs run horizontally above the tubs and supply hot and cold to the 3 tubs....he connected into the cold line to supply a line to the outside.( big old house circa 1894)

Any suggestions on how to correct? everytime I do laundry upstairs on cold and happen to have the outside sprinklers on I get only hot water in wash tub....it is a pain!