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

HOT FALT on a Balboa hot tub: hot fault at last power-up

A pump appears to have been stuck on the last time the spa was powered. Turn the spa off at the breaker, do not enter the water, and call for service.

Also shown as: M035, Hot fault, HOT FAULT

Most likely causes

  1. 1Stuck pump relay on the circuit boardmost likely
  2. 2Failed topside panel sending a constant signalless common

What to try, in order

  1. Turn the spa off at the breaker or disconnect.
  2. Stay out of the water until the temperature is confirmed with a thermometer.
  3. Contact a spa technician and give them the message code M035.

HOT FALT questions

What does M035 mean?

M035 is a hot fault. The system recorded that a pump seemed stuck on when the spa was last powered.

Can I reset a hot fault?

It may clear with a power cycle, but the cause is likely still there. Have the board checked before trusting the tub.

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.