Hi , My question is about my gas water heater. Sometimes the water gets hot and than occasionally it will not. What could be causing this ?

As you pull hot water out of the tank cold water enters in. It could be that you made a large draw and it's just reheating the water. Perhaps if you gave us more details we would have more of a answer for you. Regards, Tom

As you pull hot water out of the tank cold water enters in. It could be that you made a large draw and it's just reheating the water. Perhaps if you gave us more details we would have more of a answer for you. regards, Tom
Thanks for you're response. But it varys from one day to the next. It will go for days with plenty of hot water and then hardly get lukewarm. And nothing has been used beforehand.

Next time you have cold water and the gas isn't on, give the thermostat/gas valve a slap. If the gas comes on, the unit is bad.