What to Do if You Run Out of Hot Water

Running out of hot water is never pleasant, especially in the middle of a nice hot shower. We may not realize how much we take for granted having hot water readily available until it’s not there.

There are various reasons you could be running out of hot water, and we’ll explain some of them here.

Here are a few things that may be causing hot water problems and what you can do to fix them:

1. You may have too many appliances drawing hot water at the same time.

If you’re taking a shower while using the dishwasher or washing machine, or multiple people are taking showers at once, your water heater may not be able to supply enough hot water.

Once you’ve used all the hot water in the tank and run out of hot water, your water heater needs time to recover. You’ll just keep adding more cold water to the tank if you try to draw hot water when the water heater is in recovery mode.

Try staggering the hot water usage in your home, so you’re not using so much hot water at one time. Also, run your dishwasher in eco mode, which uses less water, and install water-saving showerheads.

2. Your water heater thermostat may be set at the wrong temperature.

Water heater thermostats have a default setting between 120-140 degrees Fahrenheit.  If yours is set below 120 degrees, raise the temperature setting. A thermostat set below 120 degrees may not provide enough hot water and can promote bacterial growth.

A water heater thermostat setting of 120 degrees usually provides enough hot water for most households. You can increase the temperature setting a bit but never go past 140 degrees to avoid the danger of scalding.

If you still have no hot water, the thermostat may be broken, or the water heater may be malfunctioning. Call a professional to have it checked.

3. A circuit breaker may have tripped.

Water heaters are required to have a dedicated circuit on your home’s electrical panel.

If your water heater isn’t producing any hot water, the circuit breaker may have been tripped. You can reset it by turning it off and then back on again on the main circuit panel for your home.

If that doesn’t fix the problem, the water heater may need repair or replacement by a professional.

4. The dip tube in your water heater may be damaged.

The dip tube is the long plastic tube that runs cold water down to the bottom of the water heater tank. The tube sits in the water in the tank and can eventually wear down and break.

If the dip tube is damaged, cold water will mix with the warmer water so that the water coming out of your tap won’t feel hot.

Check your drain strainers, appliance filters, and showerheads. If you notice small pieces of plastic there, your water heater may have a broken dip tube.

Call a plumbing pro at Chas Roberts to repair or replace it, as replacing a dip tube is not a do-it-yourself project.

5. Your water heater may have sediment buildup in the water tank.

Over time, mineral sediment builds up in the tank of your water heater and settles at the bottom. It takes up space in the tank and prevents the water from being heated properly. It also reduces the energy efficiency of your unit and can clog your water lines.

Water heaters should be flushed once a year. If you haven’t been flushing your water heater annually, you may have excessive sediment buildup in the tank that’s preventing you from having enough hot water.

You can attempt to flush it yourself if you’re confident you can do it correctly or contact a professional at Chas Roberts to flush the tank for you.

6. Your water heater may not be well-insulated and is losing heat.

If your water heater is older, it may not be well-insulated enough to keep your water warm. Many newer water heaters are well-insulated to avoid heat loss, but older models may not be.

Water tanks have a thermal resistance (R-value) rating that reflects standby heat loss. The higher the R-value, the better. If the R-value of your unit is 16 or lower, you should consider adding insulation around the tank.

Insulating the tank will keep the water warmer by reducing standby heat loss and saving you money on your water bills. Insulating your hot water pipes can help raise the water temperature by 2-4 degrees Fahrenheit.

7. Your water heater is too small for the hot water needs of your household.

If your family has grown, your current water heater may not be large enough to accommodate your household’s increased hot water demands.

Water heaters range in size from 20-80 gallons.

If you’ve outgrown your current water heater and your household is continually running out of hot water, it’s probably time to purchase a larger water heater.

To know what size to purchase, you’ll need to calculate your peak hour demand.  Storage tank water heaters have an Energy Guide label attached to the tank, and it lists a first-hour rating (FHR) that shows how much water you’ll get from the tank in the first hour of use, starting with a full tank.

You use this rating to determine what size tank you’ll need.

First, you need to figure out when your family uses the most water each day. The energy.gov website has a calculator that you can use to estimate the first-hour-rating for your household.

That will help you determine the correct size water heater to purchase.

8. Your water heater is ten years old or older.

According to the U.S. Department of Energy, about 27 million U.S. households have a water heater that’s more than ten years old. Heating water is the second largest expense in your home, accounting for 14-18% of your home’s utility costs.

Water heaters become less efficient at heating water over time and can cost more to operate.

Check the date on your unit. If it’s ten years old or older, it’s probably time to purchase a new, more energy-efficient water heater that will produce more hot water and save you money on energy costs.

Keep in mind the cost of operating the water heater as well as the price. The least expensive unit may cost more to operate than a more energy-efficient unit that costs more to purchase.


Chas Roberts

Chas Roberts has been family-owned and operated for over 75 years and is the largest HVAC and plumbing supplier in Arizona, with the highest skilled technicians in the industry.

We’re committed to the values of integrity, honesty, and trust established by our founders. Contact us for all your HVAC and plumbing needs.