Sediment or rust in the tank. Water contains minerals, even if it comes treated from a municipal water source. The higher the concentration of the minerals, the "harder" the water is said to be. When hard water sits in a hot water tank, these minerals tend to sink to the bottom and collect. Since most hot water heating elements are on the bottom, these minerals can coat or even partially cover the heating element, reducing the temperature of the water. Rust can also gather in a hot water tank and increase with age, causing the same issues. A faulty thermostat. If the thermostat on your hot water heater is malfunctioning, it may be telling the appliance that the water is at the proper temperature when it isn't. If your hot water heater is ten years older or more, this is a possibility.
A baddip tube. The dip tube deposits fresh water into the the hot water heater at the bottom near the heating element. Since heat rises, this allows hot water to be accessible at the top of the tank while the water warms from the bottom. If the dip tube is damaged, it could be dropping fresh water near the top of the tank, which would lower the temperature of the water coming out of the hot water faucet.
Wrong sized water heater. If you buy a new and larger appliance that uses hot water or you increase the number of people in your home, your demand for hot water could be exceeding the available supply. Think about the demand you are placing on the water heater. Has it increased without increasing the water heater itself?
Too much demand at one time. Even the best water heater can't keep up with simultaneous showers, dishwashers and clothes washers. Take a look at the time frame in which you are demanding hot water from the system and make necessary adjustments.
The Geiler Company offers a full line of tank based and tankless water heaters, along with the experience and expertise to determine your hot water needs for now and in the future. We can also professionally install your new hot water heater so you know the job has been done right.