Water Heaters - Another water heater problem....

I've got an older A.O. Smith gas water tank and its acting up on me. In Sept, I replaced the thermocouple because the pilot kept going out. It was good for about a month and a half...no, it keeps going out. I'm having to relight it 2 times a day just to get hot water. I know the thermocouple is good. I'm suspecting the gas burner control....

I'm curious if anyone on here as changed one out. It doesn't look that complicated, but I'm hesitant to start disconnecting lines and such. Any tips would be greatly appreciated.

29 views and no advice or help?

29 views and no advice or help?

Make that 30 and I will try and help. How old is the unit? By your name I'm assuming you are in the trades?? If yes do youhave a meter that will read millivolts and do you have an adapter for t'couples?

Make that 30 and I will try and help. How old is the unit? By your name I'm assuming you are in the trades?? If yes do youhave a meter that will read millivolts and do you have an adapter for t'couples?

Thanks for replying...yes, I am in the trades, I'm an aircraft mechanic. I do have a meter, but no adapter...i'm confidant that the thermocouple is working properly. I am in the process now of draining the tank and gettin ready to remove the thermostate unit, if the dang tank would hurry up and empty, I know I turned the water off but it sure seems like its refilling while its emptying..lol

Sorry about the delay in answering, but there was something wrong with the computer system this weekend and I just got back to normal recently.

Did you make sure the thermocouple is tight on the connection end, and how does the pilot flame look? Sometimes the pilot must be adjusted. Does the flame hit the middle to top of the thermocouple very well?

Does the pilot stay lit?

If the pilot is staying lit and this is an older water heater, it is most likely the valve. Drain the tank, unhook all lines going to the valve,(pilot, thermocouple, gas line).
Make sure the gas line is turned off !!!
Remove the valve with a large pair of pliers and then replace new valve using some type of thread sealant. Fill water heater before trying to fire W/H.

Thanks for replying...yes, I am in the trades, I'm an aircraft mechanic. I do have a meter, but no adapter...i'm confidant that the thermocouple is working properly. I am in the process now of draining the tank and gettin ready to remove the thermostate unit, if the dang tank would hurry up and empty, I know I turned the water off but it sure seems like its refilling while its emptying..lol

If you are sure or pretty surethe problem is mechanical and not something else causing the outage and you want to change the thermostat, here's how:
Turn off water to tank, if you must turn off whole house do so.
Open hot water faucet to tank pressure off of tank. Close faucet. AT THERMOSTAT. Disconmect gas supply line, pilot tube, thermocouple and burner tubing. Next loosen thermostat, you may need to install a long nipple in the inlet for leverage or use a large pipe wrench (14 or 18 should do)
have new thermostat ready to insert, meaning have the threads doped or taped. When you remove old tstat only a couple of burps of water will escape, however insert new tstat quickly and reconnect all lines.

I did all of the steps you guys suggested. It was more than a few burps of water though...lol It was enough to fill 2, maybe more 5 gallon buckets.

I got the new one installed with the pipe dope and all that good stuff, got all the lines hooked back up, filled the tank with water, and lit it for the first time.....it lit and when I let off of the pilot knob, it stayed lit!! Before, as soon as I would let off of the knob, it would go out. I set the dial to the desired temp, and the burner came on nice and smooth.

The big test will be, is it still lit when I come home tonight after 8 hrs. We shall see.

I did all of the steps you guys suggested. It was more than a few burps of water though...lol It was enough to fill 2, maybe more 5 gallon buckets.

I got the new one installed with the pipe dope and all that good stuff, got all the lines hooked back up, filled the tank with water, and lit it for the first time.....it lit and when I let off of the pilot knob, it stayed lit!! Before, as soon as I would let off of the knob, it would go out. I set the dial to the desired temp, and the burner came on nice and smooth.

The big test will be, is it still lit when I come home tonight after 8 hrs. We shall see.

Glad you got it.
If you hadn't started to drain, it wouldn't have drained anymore then a burp. I've done it many times.