It’s good to know different Water heater parts. Many people don’t know the difference between the T&P and expansion valve. The difference is the T&P valve on your water heater which is the part of the water heater in the middle of the hot and cold water feeds on the top of the water heater tank and this is a safety device that is meant to relieve pressure. If your tank is overheating, this is a safety device that if leaking there is a reason and either the water is getting too hot or the valve is bad and needs to be replaced. The reason why it’s not good to cap this is that if capped and it needs to relieve the pressure and can’t it is like a bomb in your Apopka Florida home. If it is leaking, we at Drain Genie Plumbing suggest calling your local Apopka plumber to check it out. The expansion valve is similar but this device is located usually on the top of the heater on the cold side. This is another safety device that when your water heater heats and when the water expands, it will relieve from this device. Usually when this valve goes bad you will notice water coming out of a pipe on the side of your home. If you need water heater repairs in Apopka FL call us at 407-710-0210.  
Expansion Valve
Expansion Valve
We also serve Orlando, Longwood, Lake Mary, Winter Park, Casselberry, Apopka, Maitland, Deltona, Altamonte Springs, Oviedo, Sanford, Winter Springs,  and all of Central Florida