Ask Bob Plumbing How do I fix a shower that won't stay hot?
Back to Plumbing

How do I fix a shower that won't stay hot?

A shower that loses hot water is usually caused by a failing thermostatic mixing valve or a water heater that is undersized for your household's demand. Check if the water heater thermostat is set to at least 120 degrees. If the shower has a pressure-balancing valve, it may be reacting to other water use in the house. A plumber can test the mixing valve and replace the cartridge if it is no longer regulating temperature properly.

Why It Matters

An inconsistent shower temperature is frustrating and can indicate a failing valve or an undersized water heater that needs replacement to meet your household's needs.

Related Questions

How do I shut off my main water valve? How do I unclog a toilet or drain? Why is my water pressure low? How do I know if I have a water leak? Should I repair or replace my water heater?

Need Professional Help?

Bob recommends reaching out to a trusted local professional.

Plumbing Professionals Plumbing

Still Need Help?

Bob answers every question personally. Send your question directly to him.

Ask Bob Directly