When I try to relite the pilot it lites but as soon as I let go of the button it goes back out. I've tried replacing the thermol couple but I still had the same results.I just got the water heater from a friend its only a year old and it's a whirlpool.. I've had it hooked up for 5 days before it did this. Can anyone help me??

Some Whirlpool HW heaters, from Lowe's, are covered by a special repair package. Was this bought at Lowe's? If it was, call them for details. Sounds like the problem they have been experiencing. Good Luck

It is rare, but sometimes you can buy a new thermocouple that is faulty. Also make sure that the flame is surrounding the tip of the thermocouple.

A faulty gas valve will also cause this problem. You can check the gas valve by using an ohm meter. Read between the center of where the thermocouple screws in and ground. You should have a high reading of several kilo-ohms. Look at a new one and get the reading to know exactly how many ohms it should be. There is a coil in the gas valve that keeps the gas turned on via the electricity made by the thermocouple. It makes a few millivolts when the flame is on the 3/8" of the tip. Too much flame on tip will keep it from working.