Common causes
Sediment buildup. Sediment from hard water takes up space in the tank and insulates water from the burner, reducing the hot water you get.
Broken dip tube. The dip tube sends cold water to the bottom of the tank. If it breaks, cold water mixes at the top and your hot water runs out quickly.
Failed lower heating element. In electric heaters, a burned-out lower element means only the top portion of the tank heats.
Thermostat issues. A faulty or low-set thermostat can make hot water feel short.
Undersized water heater. If your family has grown or you added a large tub, your tank may simply be too small.
Fixes
Many of these issues can be repaired. Our water heater repair plumbers test elements, thermostats and dip tubes and flush sediment.
If the tank is too small or old, water heater replacement with a larger tank or a tankless water heater gives you more hot water.
Also consider a hidden hot water leak, especially under the slab. Warm floors are a clue; see slab leak detection.
Quick Answers
Can I fix a broken dip tube myself?
It is possible but involves draining the tank. A plumber can do it quickly and check other parts.
Will tankless solve running out of hot water?
A correctly sized tankless unit provides continuous hot water.