Hydro-Quip · Hydro-Quip digital control systemsStop using the tub

OH on a Hydro-Quip hot tub: overheat protection

The water has gone above the safe limit, about 112°F on most systems, and the spa has shut the heater down. Do not enter the water until it cools.

Also shown as: OHH, overheat

Most likely causes

  1. 1Dirty filter restricting flowmost likely
  2. 2Pump run time too long in hot weathercommon
  3. 3Faulty temperature or hi-limit sensorless common
  4. 4Stuck heater relay or contactorless common

What to try, in order

  1. Stay out of the water and remove the cover.
  2. Check the temperature with a thermometer.
  3. Turn off power at the breaker and clean the filter.
  4. When the water has cooled, restore power and confirm good flow.
  5. Reduce filter cycle time in hot weather.
  6. If OH returns, turn the tub off at the breaker and call for service.

OH questions

Is it safe to use the tub with OH showing?

No. Wait until the water is at or below 104°F and the code has cleared.

Many Hydro-Quip packs use Balboa boards. Does that change the code?

If your Hydro-Quip pack has a Balboa board and panel, use the Balboa code list. The meaning of OH is the same either way: overheat.

Related codes

Balboa OH · Heater overheatGecko OH · Spa water overheatJacuzzi / Sundance OH · Overheat protectionHydro-Quip FLO · Flow or pressure switchHydro-Quip Sn1 · Hi-limit sensor faultHydro-Quip Sn3 · Temperature sensor fault

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