Balboa · BP series (TP400, TP600, TP800, TP900, spaTouch panels)Stop using the tub

HTR TOO HOT on a Balboa hot tub: heater overheat

One of the sensors in the heater read about 118°F and the spa shut down. Do not enter the water. Reset is possible once the heater cools below about 108°F.

Also shown as: M030, OHH, The heater is too hot

Most likely causes

  1. 1Low flow through the heater from a dirty filtermost likely
  2. 2Air lock or closed valvecommon
  3. 3Failed sensorless common
  4. 4Stuck heater relay on the circuit boardless common

What to try, in order

  1. Stay out of the water and remove the cover.
  2. Check the water level and top up if low.
  3. Turn off power at the breaker and clean the filter.
  4. Restore power, confirm water is flowing from the jets, and press any button to reset once it has cooled.
  5. If the message returns, switch the tub off at the breaker and call for service.

HTR TOO HOT questions

What does M030 mean?

M030 means a heater sensor detected about 118°F. Older Balboa panels show the same condition as OHH.

Is the water itself that hot?

Not always. The sensors sit inside the heater, so slow flow can overheat the heater while the tub is still at normal temperature. Check with a thermometer before getting in.

Related codes

Balboa -- · Temperature not yet knownBalboa CHEK PH · Maintenance reminderBalboa CLN FLTR · Filter reminderBalboa CNFG FAIL · Configuration errorBalboa dr · Heater may be dryBalboa dry · Heater is dryBalboa Ecn · Economy modeBalboa FLO · Low water flow

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