We have all been there at some point. We jump into the shower and there is not enough hot water. There are a number of reasons this can happen.
The Thermostat, which controls the temperature of the water, could be failing. When these units get old enough (like everything else) they do not always come on when they should and so the water in the tank will not be as warm as it should be, hence the cold shower. This is a typical cause but is a little tricky for homeowners to diagnose.
Another issue could be a buildup of sediment in the tank of the hot water heater. This happens over time and will reduce the ability of the tank to produce hot water. Fortunately this is one homeowners can troubleshoot.
First, turn off the gas power to the tank. Then turn off the in water inlet valve to the tank, this is typically located at the top of the tank. If any questions call your local hardware or home improvement store and they can tell you what to look for in finding valve, or if you have the owner’s manual for the tank it will tell you.
There is a drain valve at the bottom of the tank. Attach a hose to it and run the hose to the floor drain or into a large bucket. Turn on the valve and the water in the tank should run out. Make sure one hot water faucet, somewhere in the house is turned on, so that the tank will drain completely. Any build up sediments will run out with the water.
Retrace your steps here and see if the capacity of the tank has improved.
Another potential source of not enough hot water is a defective dip tube. Particularly on older water heaters these are notorious for cracking or splitting. These tubes carry cold water to the lower part of the water heater, but if they crack or are damaged then cold water gets elsewhere in the tank where it does not belong, and it affects the hot water supply. Again, a homeowner would have a hard time diagnosing this problem.
Try draining the tank, to see if mineral sediment build up is the problem. If your still getting enough hot water than we suggest you call in a professional to diagnose the problem.
Hot water heaters do wear out. If yours is older than 12-14 years, and you are experiencing continuing problems than you should replace the unit. There are many more energy efficient models on the market than 15 years ago.