Quick answer
If your water is warm but never hot, start with the setting: about 120°F is typical, and gas controls marked Warm or Vacation are low. Electric heaters with a failed upper element or thermostat give lukewarm water. On gas heaters, a dirty burner, a weak flame or a failing thermocouple reduces heat. Heavy sediment, a broken dip tube, or a mixing valve set low at the heater or a shower valve's limit stop can also keep water lukewarm. Check whether every faucet is lukewarm, or only one. Call (888) 217-6781 to reach a plumbing company taking calls in your ZIP.
Follow the short menu, then your 5-digit ZIP. The line goes quiet for a few seconds while it connects; stay on. If it does not connect, call once more: companies taking calls change minute to minute.
Written & reviewed by Marcus ReedIICRC WRT
Reviewed November 4, 2026· Next review May 2027
Water that is warm but never properly hot is a different problem from no hot water at all. Something is heating, just not enough.
All Faucets or One?
| What you find | Where to look |
|---|---|
| Every faucet lukewarm | The water heater or a mixing valve at its outlet |
| One shower lukewarm | That shower valve's limit stop or cartridge; see shower not getting hot |
| Hot at first, then lukewarm | Element, dip tube or sediment; see hot water runs out fast |
At the Heater
- 1The setting. The Department of Energy suggests 120°F. On gas controls, Warm and Vacation are low settings.
- 2A mixing valve. Some heaters have a thermostatic mixing valve on the hot outlet that blends in cold water. If it is set low or failing, water stays lukewarm.
- 3Gas heaters. Look at the burner through the sight glass: a steady blue flame is normal. A small, yellow or lifting flame points to a dirty burner, a venting problem or low gas pressure.
- 4Electric heaters. A failed upper element or upper thermostat gives lukewarm water. See water heater element replacement.
- 5Sediment. A heavy layer slows heat transfer on gas heaters and can bury the lower element on electric ones.
Talk to a plumber about this
One call reaches a plumbing company taking calls in your ZIP.
Safety
Do not raise the setting far above 120°F to compensate; CPSC warns hotter water raises scald risk. Turn off the power before removing electric access panels. If you smell gas, leave and call the gas utility from outside.
The Call
Call when the setting is right, every faucet is lukewarm, and the flame or elements are suspect. (888) 217-6781 connects you to a plumbing company taking calls in your ZIP. Follow the short menu, enter your 5-digit ZIP and stay on while it connects; if it does not connect, call once more, because the companies taking calls change minute to minute.
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Frequently Asked Questions
Why is my water heater not getting hot enough?
A thermostat set low, a failed element or thermostat on electric heaters, a dirty burner or weak gas supply, sediment, a broken dip tube, or a mixing valve set low.
What temperature should a water heater be set to?
The Department of Energy suggests 120°F for most homes. CPSC notes that lower settings also reduce the risk of scalds.
Why is only one shower lukewarm?
That shower's valve has a limit stop set low or a worn cartridge. If every faucet is lukewarm, the problem is at the heater.
Sources
- U.S. Department of Energy: tips for lowering water heating costs
- U.S. Consumer Product Safety Commission: tap water scalds
Methodology: How we source and verify data · Report an error
Disclaimer: HearthDry is an independent educational resource. This article is for informational purposes only and does not constitute professional, legal, or insurance advice. Consult licensed professionals before making decisions about your property or insurance claims.
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