Shower Is Too Hot Or Cold

Is Your Shower Too Hot/Cold?

At this time of year, hot showers are valued and many homeowners change the temperature of their hot water heater to reflect their desire for warmth. Still, some homeowners find it difficult to find the perfect equilibrium in their hot water heater, and the result is a shower or bath that runs too hot or too cold. Other baths and showers simply run too hot or cold, regardless of the hot water heater temperature. There are several options for solving this problem.

Adjust the Hot Water Heater Temperature

It’s possible your shower runs hot or cold because you just haven’t found the right temperature setting for your hot water heater. In general, 120 degrees Fahrenheit is considered to be the magic number for hot water heaters. This temperature is warm enough to stem the growth of bacteria in the hot water heater, and also warm enough to reach a perfect hot temperature in your shower.

In homes with young children or elderly occupants, 120 degrees may be too hot. Homeowners living with young children or elderly relatives should consult with a physician before changing the temperature on the water heater.

On some hot water heaters, adjusting the temperature is as easy as turning a dial. However, on other hot water heaters the temperature setting is hidden behind a panel. Follow these steps to remove the panel and adjust the temperature in your hot water heater to a toasty 120 degrees.


  • Philips head screwdriver
  • Flat head screwdriver


  1. Turn off the power to the hot water heater by flipping the corresponding circuit in the circuit breaker.
  2. Use the phillips head screwdriver to remove the panel covering the temperature dial on the water heater. This panel cover will likely be marked to indicate that it covers the temperature dial.
  3. Remove the insulation behind the panel cover.
  4. Use the flat head screwdriver to adjust the temperature setting.
  5. Replace the insulation and panel cover on the hot water heater.
  6. Turn on the power to the hot water heater.

Adjust the Shower Valve

The mixture of hot water and cold water available in a shower or tub can be adjusted at the shower valve stem, the part found under the faucet. The exact process for adjusting the hot and cold water will depend on the type of faucet in your shower or tub, but the general idea is as follows:

  1. Remove the handle. You may need a screwdriver to do this.
  2. Take off the metal cover beneath the handle, exposing the valve stem. You’ll see a plastic part around the valve stem. This plastic part is known as the “rotational stop limit,” (RSL). This is the part of the shower that controls the mixture of hot and cold water coming out of the faucets. The directional controls will probably be noted on the RSL, but in general a counter-clockwise turn will release more hot water, and a clockwise turn will release less hot water. To turn the RSL, you may have to pull out the RSL cover to reveal the teeth that hold the RSL in place.
  3. Turn the RSL two notches in whichever direction desired, then put the RSL back in place.
  4. Replace the faucet handle, then test the mixture of hot and cold water. If the mixture is still not correct, repeat steps 1 through 3.

There are several videos on YouTube that document this process. We’ve posted one below:

For more information for your specific faucet, look in the manual that came with your faucet. If you don’t have the manual (many people don’t), you can likely find directions or a video online by typing the model of your faucet into a search engine along with the keywords “adjusting rotational stop limit.”


In addition to the YouTube videos above, there are several online resources that may help you adjust the hot and cold water in your shower or tub. Here are a few:

  • Handyman How To: This online resource includes a very useful step-by-step tutorial with a helpful picture and an informative section about water temperatures as they relate to bacteria and scalding danger.
  • Apartment Therapy: This website has a very lengthy explanation about the best temperature for water heaters and how to prevent children from being scalded.

Note that if you’re installing a new faucet, the rotational stop limit may be at the coolest setting for liability reasons.

When in doubt, you can always contact a plumber to help you adjust your shower’s hot and cold settings. Residents of the Pittsburgh area can call Terry’s Plumbing. We’re happy to make any necessary adjustments to your faucets or water heater.

2 thoughts on “Is Your Shower Too Hot/Cold?”

  1. Bhavin Patel says:

    I not only adjusted, but also replaced the mixing valve to the shower. I am still getting luke warm water. Not sure what the problem could be. The hot water pipe to the shower is hot. Water everywhere else in the house is hot. Just this one shower is getting warm water.

  2. David Lake says:

    I replaced both top & bottom elements & both thermostats have cleaned the mixing valve on top of the tank the water is some warmer but could still be warmer yet what can be the problem yet

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