Why Do I Run Out of Hot Water So Fast in the Shower?

Freezing … That’s how you’d describe the water in your shower after several minutes. There are reasons this is happening.

Here are 4 common ones:

1) Multiple hot water appliances running simultaneously

Simultaneously running too many other hot water appliances will leave you in a deep freeze in the shower.

Dishwashers and washing machines are your biggest hot water hogs. So, try to schedule your showers when those aren’t running.

2) Water heater tank size is too small

Do you have more family members since you first bought your water heater? Did you move into a home that had a smaller family? Did you buy a smaller water heater to save money?

If you said “yes” to any of these, it’s possible your current water heater can’t meet your family’s hot water needs.

To see if your water heater can meet your needs, try this:

Calculate your peak hour demand. That’s the highest amount of hot water you use in your home in any 1-hour period. Don’t worry about having to calculate this yourself, just use this peak hour demand worksheet.
Find your water heater’s first hour rating (FHR). It should be in the top left corner of the yellow Energy-Guide label on the water heater. This is the amount of hot water the water heater can supply in an hour if it’s full of hot water.
Compare the two ratings. Is your FHR within a gallon or two of your peak hour demand? Or is your peak hour demand much higher? If it’s the latter, you need a larger water heater or low-flow showerheads to decrease the amount of hot water used while showering.

Learn more about buying water heaters in these articles:

3) Water heater dip tube is broken

The dip tube pushes cold water to the bottom of the tank so the heating element can heat it.

But a broken dip tube will shoot cold water into the top of the tank, preventing it from being properly heated.

If you find small bits of plastic in the shower head or clogging a strainer, this is your problem.

4) Sediment build-up

Imagine you have a drinking cup with a rock in it. The rock takes up space in the cup so there’s less room for water.

That’s what sediment does to your water heater. Sediment (fine minerals carried in by the water) builds up in the water heater tank over time and takes up space so there’s less room for hot water.

If this is your problem, your water heater needs flushing.

Learn more in this article: “Should I Flush My Water Heater”?

Next steps

For further information about how to solve this problem, ask one of our plumbing experts for help.

Mr. Plumber has been serving the plumbing needs of homeowners in the greater Atlanta metro area since 1966. Contact us online to ask us a plumbing question or set up an appointment.