Delta shower faucets have a single-handle operation valve for both hot and cold water. The higher and lower temperature ranges are adjustable, but it requires removing the faucet handle and the trim to access the valve. You may want to adjust the temperature of the faucet in summer or winter to produce hotter or cooler water more quickly.
Removing the Faucet Handle
Plug the bathtub or shower drain so that if small parts are dropped they won't be lost down the drain.
Turn off the water-supply for the shower faucet. This valve is usually behind the wall or in the laundry room and accessed in the adjoining room or by faucets located in the laundry room. If the water-supply faucets are not accessible, turn off the house main water supply.
Locate the rubber cap that covers the set screw in the faucet handle. Pull this off with the needle-nose pliers and place in the container.
Remove the set screw using the Allen wrench or Phillips screwdriver. Place this in the container.
Pull the single-lever faucet handle off the faucet stem. It may be difficult if calcium deposits have built up.
Adjusting the Temperature
Remove the inner ring located beneath the handle. Both rings may fall out. Place these in the container.
Turn the exposed lever counter-clockwise to increase the temperature and clockwise to lower the temperature.
Reverse the instructions for removing the handle to reattach the handle.