Thermostat Replacement or Calibration

Note that the purpose of this section is to show you how to increase the temperature setting or replace the thermostat switch on an electro-mechanical, capillary tube type thermostat switch. This requires disassembly and reassembly of the spa side control housing, or removal of the thermostat device from a heater casing, deck mounting plate, or other switch encasement, and the reassembly of the switch and its components.

If you have a thermostat that has a very small COPPER or Stainless Steel tube coming from it, then you should be able to perform this procedure. Note that some later model controls utilize electronic or digital thermostats which do not have this small tube, and actually looks like a black inslulated wire. With this type of control, the ONLY recommended course of action is to REPLACE the entire control box or thermostat assembly.

Recalibration is NOT an exact procedure. Since these types of thermostats only provide relative indications of hot or cold water, replacement with a new capillary type thermostat is recommended for safety reasons.

In view of the fact that most of these types of thermostats will lose their maximum temperature sense rating over time, and recalibration is all that is typically required, this procedure is presented to show you how an experienced spa technician may solve this problem quite easily, without actually having to replace the thermostat switch.