Hello if I want to drain 2 or 3 gallons of water from the water heater.do I have to turn the pilot off.
Thank you.

Why do you want to drain off two gallons.

You know it will back fill the water into the tank?

Why not just fill up a two gallon container in the bathtub?

The answer to your question is no but we sure don't understand what you are doing.

Im currious also. What are you trying to achieve? Please give us better description of what you are doing and why, and we will try to answer your question.

Why do you want to drain off two gallons.

You know it will back fill the water into the tank?

Why not just fill up a two gallon container in the bathtub?

Well Iread that if you do that to the water tank every 3 months it will keep the tank clean
From all the junk that accumulates on the bottown of the tank.
Thank you.

This is called, "flushing the water heater". You're on the right track. To flush a heater the power does not have to be turned off. Let me show you how it's done.
For long life and fewer troubles you should keep your heater clear of mineral build-up by FLUSHING NOT DRAINING on a regular schedule. Attach a hose to the boiler drain at the bottom of the tank. With the pressure on, open the boiler drain and let it run until the water runs clear. You will see a spurt of red,(rust) followed by white or yellow grains,(lime or calcium carbonate). This shouldn't take more then a few minutes. Do this monthly to keep it clear. Now flush out your hot water lines on ALL fixtures that are affected . Now pull each aerator and clean the screens. Be sure you put them back together the same way you took them out. Don't forget to flush it out every month. Your heater will thank you for it. Hope this helps and thank you for rating my answer, Tom

OK now this makes sense but you should follow Tom's advice. Be sure to flush for several minutes, not just 2-3 gallons. Its OK to leave the pilot light on during the flush.

Calvarez,

Just to make sure I'm on the same page as you, you are talking about a gas heater, not electric, correct?

This is called, "flushing the water heater". You're on the right track. To flush a heater the power does not have to be turned off. Let me show you how it's done.
For long life and fewer troubles you should keep your heater clear of mineral build-up by FLUSHING NOT DRAINING on a regular schedule. Attach a hose to the boiler drain at the bottom of the tank. With the pressure on, open the boiler drain and let it run untill the water runs clear. You will see a spurt of red,(rust) followed by white or yellow grains,(lime or calcium carbonate). This shouldn't take more then a few minutes. Do this monthly to keep it clear. Now flush out your hot water lines on ALL fixtures that are affected . Now pull each aerator and clean the screens. Be sure you put them back together the same way you took them out. Don't forget to flush it out every month. Your heater will thank you for it. Hope this helps and thank you for rating my answer, Tom

Thank you very much guys I really apreciate the help have a great day.
Carlos

Calvarez,

Just to make sure I'm on the same page as you, you are talking about a gas heater, not electric, correct?

Cal,
The flushing procedure's the same for either gas or electric, in this case gas.
Regards, Tom