Balboa · VS / GS seriesStop using the tub

OH on a Balboa hot tub: heater overheat

A sensor at the heater read about 118°F and the spa shut itself down. Do not get in the water until it has cooled and the code has cleared.

Also shown as: OHH, HH, overheat

Most likely causes

  1. 1Low flow through the heater from a dirty filtermost likely
  2. 2Pump running too long in hot weather with the cover oncommon
  3. 3Air lock or closed valve starving the heater of watercommon
  4. 4Failed temperature or high-limit sensorless common
  5. 5Stuck heater relay on the circuit boardless common

What to try, in order

  1. Do not enter the water. Take the cover off and let the tub cool.
  2. Once the heater has cooled to about 107°F, press any button on the panel to reset.
  3. Check the water level and top it up if it is low.
  4. Turn off power at the breaker, then remove and clean the filter.
  5. In summer, shorten the filter cycles so the pumps add less heat.
  6. If the code returns with a clean filter and good flow, turn the tub off at the breaker and book service.

OH questions

Is it safe to use a hot tub showing OH?

No. Water above 104°F can cause heat stroke, and the code means part of the system read about 118°F. Wait until it cools and the code clears.

Why does my hot tub overheat in summer?

Pumps add heat every time they run, and a good cover holds it in. Long filter cycles in hot weather can push the water past the set point. Cut the filter time and crack the cover open.

Related codes

Gecko OH · Spa water overheatHydro-Quip OH · Overheat protectionJacuzzi / Sundance OH · Overheat protectionBalboa -- · Temperature not yet knownBalboa CHEK PH · Maintenance reminderBalboa CLN FLTR · Filter reminderBalboa CNFG FAIL · Configuration errorBalboa dr · Heater may be dry

General guidance. Follow your manufacturer's instructions; anything inside the control box is work for a licensed professional. Updated October 5, 2026.