Troubleshooting guide
Safe hot tub temperature
The safety agencies agree on the ceiling: 104°F. Here's what they say, and why a thermometer matters.
The limits
- Never above 104°F. CPSC says hot tub water should never exceed 104°F, and the CDC gives the same limit.
- 100°F is considered safe for a healthy adult, according to CPSC.
- Pregnancy: CPSC advises pregnant women to stick to a 100°F maximum; the CDC says to talk to a healthcare provider before using a hot tub.
- Children: CPSC suggests special caution for young children, and the CDC says not to let children under 5 use hot tubs.
Use a thermometer
CPSC says to check the water with an accurate thermometer before getting in, because hot tub thermostats can be off by as much as four degrees. If the thermometer and the topside disagree by a lot, or the water keeps getting hotter than the set point, see hot tub overheating.
Other safety rules
- Don't drink alcohol before or during hot tub use (CPSC and CDC).
- People with heart disease, circulation problems, diabetes or blood-pressure problems should ask their doctor first, and people taking medications that cause drowsiness shouldn't use hot tubs (CPSC).
- Don't swallow the water, shower before you get in, and stay out if you're sick with diarrhea (CDC).
- Keep cords, plugs and electrical devices away from the water and test the GFCI monthly (see GFCI keeps tripping).
Common questions
What is the maximum safe temperature for a hot tub?
104°F. Both the U.S. Consumer Product Safety Commission and the CDC say hot tub water should not exceed 104°F.
Why does my hot tub feel hotter than the display?
Built-in thermostats can be off by several degrees, according to CPSC. Check with an accurate thermometer. If the water is hotter than the set point, stay out and have the sensors and controls checked.
Is a hot tub safe during pregnancy?
CPSC advises a maximum of 100°F for pregnant women, and the CDC says to talk to a healthcare provider before using a hot tub while pregnant.
Related guides
Hot tub overheating
Water too hot or an OH-type code. Stay out of the water and check it.
Read the guideCloudy or smelly water
Cloudy, foamy or smelly water: filters, sanitizer and pH first.
Read the guideGFCI keeps tripping
The spa shuts off and the GFCI won't stay on. Treat it as a safety signal.
Read the guideHot tub not heating
Jets run but the water stays cold. Usually it's flow, not the heater.
Read the guideSources
- U.S. Consumer Product Safety Commission: CPSC warns of hot tub temperatures (release 79-071)
- CDC Healthy Swimming: What you can do to stay healthy in hot tubs (temperature, chlorine, bromine and pH)
Brand names belong to their owners. Hot Tub Helpline isn't affiliated with or endorsed by any manufacturer. Steps and codes vary by model and year, so always check your own owner's manual.