Hot water is an amazing thing. Being able to have hot water come from your faucet when you want it instead of having to heat the water up on a stove and hauling it around to where you want it is something that everyone takes for granted — at least, right up until you turn on your hot water faucet and you don't get any hot water. When you notice that, you need to go check out your water heater to see what you need to do to get your hot water running to your faucet as soon as possible. So, what can you do to troubleshoot your water heater?
Check the Thermostat
One thing to check is what temperature the thermostat is set at. If it has somehow changed and is set at a lower temperature, that will mean that it isn't heating up the water that is being stored in the tank. One way to check to see if it is the thermostat that is causing the problem is to turn the thermostat all the way up and wait for a little while for the water in the tank to heat up and test it again. Just keep in mind that if you turned the thermostat all the way up, the water could be very hot when it comes out of the faucet, and you could get hurt if you put your hand under the water. You should be able to feel warmth from the water as you hold your hand near the stream, or it may emit steam. If the only way you get any hot water is with the thermostat all the way up, you might want to call a professional to come check it because it may be failing.
Look For Leaks
You also want to make sure that there aren't any leaks on your water heater. A leak would let all the hot water in the tank leak out of the tank, which would mean that there is always cold water coming into the tank so that when you turn it on, hoping to get that nice, hot water, you are going to get ice cold, freezing water. There are several places that you could see leaks. Check all the places where pipes connect to the heater because that's the most likely location, but you could also have leaks that come from the tank itself. Look for puddles of rusty water as one way to see if there are any leaks.
If you can't figure out why your water heater isn't giving you hot water, then it's time to call a water heater repair technician and have them come look at the problem and figure out what's going on.