Grohe produces a large line of shower and bathroom assemblies such as showers, faucets, tubs and toilets. All Grohe faucets use an integrated cartridge system that prevents the faucet or shower from giving water from a single hot or cold line. This internal temperature management system prevents users from being burned by the hot water, which is often in excess of 100 degrees Fahrenheit. Grohe also produces a line of safety shower attachments designed to prevent children from burning themselves in the tub.
Press in the safety lock located at the top of the hot water safety valve. The safety lock, if installed properly, is behind the actual hot water handle and flush against the wall. The safety lock must be depressed to move the safety valve.
Turn the circular dial of the safety valve clockwise to increase the temperature of the water. The safety valve, when attached, can only turn half way to the right (clockwise), effectively limiting the temperature to 90 percent of what your pipes are capable of without the safety valve.
Turn the circular dial to the left (counterclockwise) to activate the safety valve and reduce the maximum temperature the faucet is capable of. This in effect limits the amount of hot water that is mixed with cold water. You will always get a certain amount of cold water even if the cold water handle is in the "off" position.