Balboa · BP series (TP400, TP600, TP800, TP900, spaTouch panels)Fix soon

SNSR BALANCE on a Balboa hot tub: sensors out of sync

The two temperature sensors in the heater are reading about 3°F apart. The tub keeps running for now, but this is an early warning that a sensor or the flow needs attention.

Also shown as: M015, SENSOR BALANCE POOR, Sensors are out of sync, SnS

Most likely causes

  1. 1Reduced water flow through the heatermost likely
  2. 2One sensor drifting out of calibrationcommon
  3. 3Scale on the sensors or heater tubeless common

What to try, in order

  1. Clean the filter with the power off at the breaker, and check the water level.
  2. Run the jets for a few minutes with all jets open.
  3. Reset power at the breaker for 30 seconds.
  4. Test pH and calcium hardness and correct them if they are high.
  5. If the message stays for more than a day, book service.

SNSR BALANCE questions

What does M015 mean?

M015 means the two heater sensors may be out of sync by about 3°F. It is a call-for-service warning, not an immediate shutdown.

Can I still use the tub?

Yes, as long as it keeps heating normally and the water temperature checks out with a thermometer. If it changes to the fault version (M026), the spa shuts down.

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.