Today on a gas water heater what we are going to talk about is how to set and adjust the thermostat. This is something that is common on all gas water heaters, and it is something that every homeowner needs to use as far as or know as far as how a gas water heater thermostat is set. It is part of the gas valve. We will go over the control. The gas valve what it does it lets gas in through the bottom burner, which is actually what fires up after it proves flames, and it heats the hot water. It heats it to a point at the bottom of the tank to a temperature if you will by a thermistor that actually sticks inside of the tank itself. This is a gas valve. It has got what they call a thermistor in the back side of this tank. What it is is there is a probe that actually threads into the tank, and it has a temperature sensor inside of it so as soon as the tank comes up to temperature what it does is it opens a set of contacts in the gas valve, and tells it to shut off. Which then shuts the gas off inside of here, and it stops the hot water heater from heating. This is a thermostat knob. What it does is rotate clockwise as you can see with the lettering to a warmer temperature all the way up to hot. This is a setting I do not recommend we will start there. Due to scalding hazard both in children and elderly people you can not have the hot water up high. Anything pass one hundred and twenty degrees is just really extreme. One hundred and twenty is hot. I like to see it at one hundred and five to one hundred and ten degrees it is just where it needs to be at. This they have from the factory they come with what I call a black line or a white line setting. This one looks like it has been marked over. I typically set it one notch below that just because that's about where one hundred and ten degrees is. You can play with this, and figure out where it is at. A lot of times you can check the temperature in the house at a faucet. If if is a little hot you just simply turn it counter clockwise by each one of these little things is about five degrees on a gas valve thermostat. So you can kind of dial it in exactly where you would like to dial it in. As far as any kind of service or maintenance that you would have to do with this there is nothing that really a homeowner needs to touch on the gas valve itself besides temperature knob, and then learning how to light the pilot, and going over those things like that. The thermostat itself is attached to the gas valve, and it basically turns the temperature up or down.