Pilot light keeps going out

pilot light keeps going out! more then likely its the thermal coupling doing this. if bad it shut all gas to heater for a safety measure. just shut power off, then turn gas off and replace it. then you should be ready to go. to relight heater hold down on gas vavle knob in the pilot position, hold down and light it at the coupling where gas comes out. when it is lit, continue to hold down for 60 seconds. release knob very slow. then if its lit, turn to the run position. if flme goes out, wait at least 5 minutes to expel the gas fumes and turn to pilot and try again. good-day !

you either have a back draft blowing out the pilot light, or a bad thermal coupling. if coupling is bad it will shut down the gas flow therefore shutting off pilot light. its a safety measure to stop the gas flow if pilot goes out. replace thermal coupling, that may do it. good-day ! but shut off gas first !

Solution is probably better ventilation to gas water heater.
On hot days, heat and lack of ventilation can cause pilot outage.
Hot air causes oxygen molecules to move farther apart, and combustion is no longer supported so pilot goes out.

Open following links:
http://waterheatertimer.org/pdf/Attic-Ventilation-and-Pilot-Outage-in-Gas%20Water-Heaters.pdf
http://waterheatertimer.org/How-to-install-gas-water-heater.html#troubleshoot

You need to replace the thermocouple.
When you light the pilot it is supose to heat the thermocouple.
the thermocouple produces a small electric current which allows the gas valve to open and keep the pilot going. and allowing the main burner to come on.

Either the pilot light orfice is dirty, and you will need to pull it out and clean it, or the thermocouple is bad. If the pilot goes out as soon as you let the button go then it is most likely the thermocouple. If the pilot stays lit for a few days or hours then you will need to clean the pilot orfice, heres how:
1 turn off the gas supply
2 unhook the main burner gas line from the thermostat, this is the line that goes to the burner
3 unhook the pilot supply line it is usually next to the main burner line
4 unhook the thermocouple from the thermostat
5 remove the burner assembly
6 take the orfice out of the pilot line and clean it out by blowing thru it, use an air compressor if needed.
7 reassemble and light pilot

turn the dial to pilot and push and hold down red button while you light the pilot located inside water heater beside burner, keep holding button down after pilot is lit for about 1 minute. If you let go and pilot goes out repeat above steps and make sure pilot flame is heating up the thermal couple. If that fails replace themal couple.

YOUR WATER HEATER HAS WHAT IS CALLED A STANDING PILOT-STAYS LIT ALWAYS WHEN THE PILOT GOES OUT YOU LOOSE EVERYTHING. YOU HAVE TO REPLACE THE THERMOCOUPLE WHICH KEEP THE PILOT LIT. ONCE THE PILOT IS LIT THE THERMOCOUPLE SENDS IN MILLIVOLTS TO THE BURNER TO SAY ITS READY FOR BURNING
IF YOU ARE NOT FAMILURE WITH THIS REPLACEMENT PLEASE FIND SOME ONE WHO CAN. IT IS NOT HARD TO DO ASK A NABOR OR FRIENDS SOME HAS TO KNOW HOW. SERVICE COMPANYS ARE OUT FOR THE MONEY FOR A 10 MINUTE JOB

turn gas off the then back on then light

The pilot assembly should look similar to the pic above. Depending on where you live, you may be required to hire a certified plumber to replace the parts. If not you can do it your self. Keep in mind if it's not staying lit you also need to check the thermostat and the thermocoupler before replacing the pilot assembly. There is a good chance it is just the thermocoupler going out. It is one of the first things to check when troubleshooting a pilot light problem with a gas water heater. A thermocouple determines if the pilot light is lit. If it's not lit, the gas valve fails. If that's the problem, replace the thermocouple.

1. Shut off the gas valve on the water heater and the gas valve on the line near the heater. Remove outer and inner doors, and loosen the pilot and supply tubes and the thermocouple connections to remove the burner assembly.
2. Step 2 Loosen the screw holding the thermocouple to the bracket. Remove old thermocouple. Bring it with you to the store to ensure you are buying the proper replacement.
   
3. Step 3 Install the new thermocouple. Position the thermocouple so that the pilot flame heats 1/2 inch of the tip.
   
4. Step 4 Reinstall burner assembly in the water heater. Tighten burner supply tube, pilot tube and thermocouple connections. Tighten thermocouple no more than a quarter turn more than hand-tight.
   
5. Step 5 Turn on both gas valves. Check supply tube and pilot tube for leaks with soapy water. If soap bubbles, tighten connections to fix leak. Ignite the pilot light, and make sure the thermocouple tip is heating up. Replace inner and outer doors.