Waterheater pilot light keeps going out

There is a small probe with its tip in the pilot flame called a thermocouple,
this is a flame failure device and shuts off the pilot in the event the flame goes out due to wind water or no gas, this device can become bunrt out usually after many years of use and can normally be replaced, you can purchase a universal thermocouple from most gas appliance retailers

I had a similar problem with mine and it turned out to be a plugged air vent sceen. This is the small dome like sceen on the gas valve. I vaccumed out the unit and have not had the pilot go out in over a year.

problem is on pilot assembly that goes from temp control to burner inside..kind of expensive so u should check to see if there is an 800 number to check wrrnty info..temp control box also goes bad also

the intake screen or as is called flame trap is located on the very bottom of the heater underneath. this is very important that you keep this clean or it will keep going out. this is the only way this heater has to get air to the burning chamber.

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

The Reliance 606 has an enclosed thermal couple. Before you try taking that assembly apart take a wire brush to the bottom opening directly under the burner. There is a metal filter on the very bottom of the water heater. It could be that the filter has gotten filled with dust or animal hair. It took a serviceman 2 days to figure this out for me. The water heater has to have good airflow through that filter to work well.

The Cold air screen on the bottom of the water heater is partially plugged. That is if the pilot light can be lit and stay on, but goes out when the heater should be functioning normally. This is not the removable plastic screen but a round white-yellow grid with 1/32" holes. You can try to clean it through the bottom but you may have to remove the gas line from the controller to the burner, pilot gas line, and thermocouple connection to remove that complete assembly to get access to the screen. The AO Smith booklet warns of this but they pretend the plastic screen will keep this second screen clean but it won't. After three years it was two thirds plugged.

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

Hi. Some of the whirlpool water heaters are notorious for having plugging problems on the air inlet screen. They are the air slots under the burner. Clean the slots with a brush and re-light. You may need to clean them regularly.
Hope this was helpful!
Regards, --W/D--

Sounds like the gas valve has failed. The gas valve can be replaced. It will unscrew out of the tank. Shut the water supply to the tank off and get the new gas ready to screw in. Take out the old and screw in the new, you will onlt lose about a cup or two of water if you are quick enough. Otherwise drain the tank down if you must. If you are going to replace the gas valve I would also replace the thermocoupler.