Do You Run Out Of Hot Water?
Insufficient amount of hot water is another common water heater troubleshooting complaint. If the water heater is new, this can be caused by too small of a tank or improper installation.
If your family has grown and your tank is too small now, you can help the situation by installing a thermostatic mixing valve and set your water tank temperature higher. The typical water heater setting should be less than 120 degrees F but, by installing this blending valve, you can set it higher (to about 140 to 150 degrees) and the valve will mix cold water with this higher temperature water to provide the desired temperature at the outlet. You will use less water from the tank and so effectively increase its size.
If the unit is older, this situation can be caused by a buildup of sediment in the tank. This can usually be cured through routine maintenance.
If the routine maintenance does not cure the problem, the unit may need replaced. A general rule of thumb is that 1/2 inch of sediment in the tank can require 70% more fuel to heat the water.
The final cause of insufficient hot water can be due to the heater itself not working properly. For a gas water heater this can be caused by a bad gas control or the pilot going out. The pilot could go out due to improper venting, dirty pilot assembly, or a defective thermocouple.
On an electric water heater, insufficient hot water could be caused by the breaker being off, high temperature limit, a bad thermostat, or a bad element.