Hot Water Not Lasting? Here’s Why

There’s nothing worse than getting ready for a nice hot shower or tub soak only to discover cold water coming out of the tap.

There can be several reasons for your hot water problems. If the water just won't heat up, it’s probably because your water heater has been working overtime and needs time to regenerate; however, if your hot water shower turns suddenly chilly, the problem may lay within the unit itself.


If your water heater suddenly seems to supply less hot water than in the past, first check the water heater dial. One of the equipment issues could be a thermostat that is set too low for the size of the water heater itself. The most common setting for the temperature on the water heater is between 120–140 degrees Fahrenheit. If your thermostat were set lower, you would notice a lower volume of hot water.

Adjust the temperature dial on the front of the water heater. Wait a little while, and then check the water temperature at a faucet. If adjusting the temperature dial doesn’t do the trick, try the water heater troubleshooting methods below

Also, if outdoor temperatures have dropped significantly, your water heater must work harder to heat-up and maintain the cold inbound water. Also, because the water cools more as it travels through pipes that run through unheated spaces, you’ll need to adjust the water heater’s dial to a slightly hotter temperature. 

Faulty Thermostat

The thermostat could also be defective, in which case it may need to be replaced. You may want to contact a plumber instead of attempting to repair it yourself.


If it seems like you never have enough hot water in your home, your water heater may be too small for the demand. If the problem is chronic, or if you’ve increased your needs for hot water by installing a big new soaking tub or high-flow showerhead, you’ll probably need to get a new, larger water heater. Also, if you have a larger home with multiple bathrooms, you may need to increase the size of the water heater you are using to manage the larger demand.

Internal Problems

There may also be issues with the water heater internally, such as a bad dip tube. The dip tube is used to force the incoming cold water to the bottom of the tank to be heated. The cold water is heated which pushes the hot water up to the top of the water heater and into the hot water supply pipes. If the dip tube becomes disconnected or broken, the water in the tank would become diluted and appear as though you are getting less hot water out of the water heater.

Heater Makes Noises

Noises coming from a water heater can be caused by expanding and contracting metal parts, drips or more likely minerals and hard water scale accumulations inside the tank. When heated, dissolved hard water minerals recrystallize and form scale that cakes onto interior surfaces, making the water heater less efficient and more likely to fail.

Get Professional Help 

If you don’t trust yourself to investigate or repair, get professional help. Plumbing is a specialty trade, and even the most straightforward project can quickly turn complicated. When it comes to hot water shower problems, the diagnosis is usually simple, but the actual operation is a different story. Therefore, to avoid getting in over your head, call a professional plumber to get you up and running again so you can enjoy your time in a nice, hot steaming shower again.