The part(s) or condition(s) listed below for the symptom Water Heater runs out of hot water are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
Gas Water Heater Not Heating? Gas Water Heater Troubleshooting
Gas Water Heater Leaking? Gas Water Heater Troubleshooting
Electric Water Heater Too Hot? Electric Water Heater Troubleshooting
Electric Water Heater Not Heating? Electric Water Heater Troubleshooting
Electric Water Heater Leaking? Electric Water Heater Troubleshooting
Gas Water Heater Pilot Not Lighting? Gas Water Heater TroubleshootingThe gas valve opens to allow gas to enter the burner. If the gas valve does not open, the burner will not light, and the water heater will not heat. If not corrected, the water heater will eventually run out of hot water. First, ensure that the ignition source is working properly. Second, ensure that the gas valve has pressure. If the ignition source is working, and the gas valve has pressure, consider replacing the gas valve assembly.
The gas valve opens to allow gas to enter the burner. If the gas valve does not open, the burner will not light, and the water heater will not heat. If not corrected, the water heater will eventually run out of hot water. First, ensure that the ignition source is working properly. Second, ensure that the gas valve has pressure. If the ignition source is working, and the gas valve has pressure, consider replacing the gas valve and thermostat.
Getting the water in the tank to the right temperature is often a challenge. While most water heater thermostats or thermostat valves will have a recommended temperature designation, you will need to adjust the setting then wait and see what the actual water temperature is by checking it with a thermometer. The recommended water heater temperature is 120 degrees Fahrenheit. Temperatures above 120 degrees can increase the risk of scalding. If you have small children in the home you may want to set the water temperature lower.
The dip tube distribtues the incoming water to the bottom of the tank to ensure that all of the water is heater thoroughly. If the dip tube breaks and becomes detached from the incoming cold water pipe, the incoming water won't be properly heated. A broken dip tube will need to be replaced with a new one.
The thermostat senses the temperature in the water heater and regulates it accordingly. If the thermostat is defective, it may not sense that the water temperature has dropped and the heating element will not turn on to heat up the water. You can use a multimeter to test each thermostat to determine if the component if functioning normally. A defective thermostat will need to be replaced with a new one.
Electric waters heaters depend on heating elements to warm the water in the tank. If one or more of the elements is faulty, the water won't be heated properly. To determine if the heating element is defective, use a multimeter test it for continuity. If the heating element does not have continuity, replace it.
