Spa Helpdesk

M031

Balboa M031: sensor A fault

M031 is printed next to Sensor A Fault. The guide says a temperature sensor or sensor circuit has failed, and it says to call for service. This wording is from Balboa guide 40985-G, 26 March 2014, for BP2500 and BP2600 with a TP800 or TP900 panel. Sensor B is M032.

A temperature sensor or sensor circuit has failed.

Models this page covers: BP2500, BP2600, TP900, TP800

Do this first

  1. Power

    Do not replace the sensor yourself

    Unplug is as far as a safe stop goes if you leave the spa. The guide does not tell you to change sensor A. Leave the housing closed and call for service.

When to call a technician

Call a technician now if

  • The breaker or the RCD trips when the pump is plugged in.
  • You smell burning, see melted plastic, or the water is too hot to touch.
  • The code comes back after one reset.

Also call for these, from the manual

  • Call for service for a Sensor A fault. This page has no ohm test and no wiring diagram.

Questions

Which plug is sensor A?

This user guide does not say. It only pairs Sensor A with M031 and Sensor B with M032, then says call for service. Do not open the pack to guess the plug.

Manuals we checked