Electronic hot tub components

Flow error

Most hot tubs today are equipped with heaters that use pressure-sensing devices to ensure the unit has sufficient flow to cool itself for proper operation.

A flow error can be caused when a pressure-sensing device detects a problem. Depending on the manufacturer, several error codes (e.g., FLO, FLC or three flashing dots) have been used to help hot tub technicians determine flow errors. When in doubt, always use the manufacturer’s hotline if an error code isn’t recognized.

Before troubleshooting a flow error, first locate the pump that pushes water through the heater to verify it is working properly. The spa pack should trigger the pump to turn on when heat is demanded. If it fails to operate, troubleshoot the problem as a pump-related issue, not a flow error.

If the pump engages but no flow is detected, verify the pressure sensor is working properly. If bypassing the pressure sensor is possible, do so for test purposes only, as leaving this device on bypass is a safety hazard. If the sensor cannot be bypassed, use one of these methods to check flow related problems:

• Make sure the pump is not air locked;
• Remove the filter to check for any blockage; and/or
• Verify all air diverters are open.

If the system’s flow is working properly but a problem still remains, the next step is to replace the flow-sensing device.

Inaccurate temperature readings

When troubleshooting a temperature reading error, the first step is to confirm the problem. To do this, use a calibrated digital thermometer to compare the hot tub’s keypad reading with the actual water temperature.

If the temperature reading is within two degrees, it is possible the results are within the accuracy of the test. If the control and thermometer have a +/- one-degree accuracy, the results are within acceptable levels.

If the temperature is not accurate, the hot tub’s temperature sensor must be located. It can usually be found in the body of the water or inside the heater barrel. If it is located inside the heater barrel, it will need to be replaced (with the included probe) to correct the problem.

If the sensor is located outside of the heater barrel, place a spare sensor in the water. If the proper temperature is displayed, the problem can be narrowed down to the sensor itself or simply the way it was installed. If the new probe recreates the same problem, installation is the cause.

If placing a new probe in the water does not result in any change, replace the controller, as something is wrong on the main board.