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

STUK PUMP on a Balboa hot tub: pump may be stuck on

The water may have overheated because a pump appears to be stuck running. Turn the spa off at the breaker and do not enter the water.

Also shown as: M034, A pump may be stuck on, STUCK PUMP

Most likely causes

  1. 1Stuck pump relay on the circuit boardmost likely
  2. 2Stuck button or failed topside panelcommon
  3. 3Sensor reading higher than the real temperatureless common

What to try, in order

  1. Turn the spa off at the breaker or disconnect.
  2. Stay out of the water and take the cover off so it can cool.
  3. Check the water temperature with a thermometer.
  4. Call a spa technician before powering the tub back on.

STUK PUMP questions

What does M034 mean?

M034 means the water may have overheated and a pump seems to be stuck on. Balboa's instruction is to power down and stay out of the water.

Can a pump really overheat a hot tub by itself?

Yes. Pump friction adds heat. A jet pump that runs for many hours under a closed cover can push the water well above 104°F.

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.