Suddenly finding yourself without hot water in the middle of a once-hot shower is a very special kind of “unpleasantness.” Unfortunately, suddenly running out of hot water is bound to happen to everyone at least once in their lifetime. Getting to the bottom of the issue can take some investigation, but the good news is that it does not always require a professional’s help.
Here are some of the typical reasons why hot water can run out, along with what to do.
1. The water heater tripped the circuit breaker.
The occasional power surge can sometimes cause your large appliances to trip their circuit breaker. Head to your electrical panel to see if the switch associated with your water heater needs to be reset.
2. Your water heater’s fuel supply has been shut off.
If you own a gas or propane water heater, someone might have closed the gas valve. Without gas, your water heater can’t heat water. Ensure the valve is in the “open” position (parallel to the gas line, as opposed to perpendicular to it). If you smell gas (a “rotten egg” smell) or hear the hissing sound of a gas leak, evacuate your home at once, notify your utility company from a safe distance away, and contact a professional to repair your gas line.
3. The water heater’s pilot light is out.
Although newer water heaters no longer have pilot lights, it’s commonplace for older gas water heaters to have them. Typically, you can find instructions for relighting the pilot light somewhere on the side of the water heater tank, in the owner’s manual, or in online instructions from the manufacturer. Of course, you can always consult a qualified plumber regarding water heater pilot light issues as well.
4. There’s a problem with the water heater’s burner.
Occasionally, burners can have problems igniting. Although these issues require a repair from a trained professional, you can test to see if this is the problem (and possibly solve it) by following these steps:
- Wait for the burner to turn off. If you have no hot water, it’s probably off already. Once it’s off, set your water heater’s thermostat to 120°F.
- Go to a faucet and turn on the hot water. Let it continue to run for a minute or so while you check on the burner.
- Observe to see if the burner ignites. If it does, you can adjust the temperature as needed while the water still runs. However, the Consumer Product Safety Commission (CPSC) strongly recommends a temperature no higher than 120°F to prevent scalding.
- If your burner does not ignite, there’s most likely a problem with the thermostat. You’ll need a plumbing professional to repair it.
5. The water heater’s capacity is too small.
If you own a storage tank water heater, sometimes a couple of showers in a row can use up most of the hot water stored in the tank. Then, when it’s time for the next person to shower, they’ll run out of stored hot water partway through. You have some options:
- Wait longer before showering so the hot water can “fill up” again.
- Upgrade to a water heater with a bigger tank.
- Switch to an on-demand (or tankless) water heater.