SALUS ST620 – Restart, “HI” Message, and Factory Reset Guide

SALUS ST620 – Restart, “HI” Message, and Factory Reset Guide

The SALUS ST620 is a wireless, electronic, programmable thermostat featuring Touch-Ring technology. It allows precise temperature control with 6 daily programs, plus additional modes such as manual, holiday, service, and frost protection.
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What does the “HI” message mean?

After powering on the device or pressing the RESET button, the following message may appear on the screen:

HI

This means:

  • The device is in the startup or reset process.
  • All display segments activate for approx. 2 seconds.
  • Then the thermostat switches to NORMAL mode, displaying the current room temperature.

The “HI” message appears:

  • When the device is turned on for the first time with new batteries,
  • After pressing the RESET button,
  • After a long period of inactivity or battery depletion.

This is normal behavior and indicates the device is initializing correctly.
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Factory Reset – How to Reset the Device

Where is the RESET button?

  • Located at the bottom of the housing, next to the cover screw.
  • A thin object (e.g., paperclip or pin) is needed to press it.

What does RESET do?

  • Clears all user settings, including:
    • heating programs,
    • clock and calendar,
    • setpoint temperatures.
  • Restores default factory settings.
  • Displays the “HI” message, then enters NORMAL mode.
  • Does NOT remove RF pairing with the receiver (if previously configured).


Diagnostics – What to do if ST620 does not respond after reset

Symptom

Possible Cause

Solution

“HI” message doesn’t disappear

Weak or depleted batteries

Replace with new alkaline batteries

Screen doesn’t light up

Sleep mode is active

Touch and hold the ring for 3 seconds

Settings cannot be changed

Keypad lock is enabled (LOCK)

Slide switch to UNLOCK

Device completely unresponsive

Batteries inserted incorrectly or dead

Reinsert batteries and press RESET


Battery Information

  • Use only alkaline AA batteries (2 pcs) – do not use rechargeable batteries.
  • When battery power is low:
    • LCD backlight may not work,
    • The thermostat may enter OFF mode (all outputs disabled),
    • A RESET may be required after battery replacement.
  • If the screen does not turn on after changing batteries, press RESET to restart the device.

Summary

The “HI” message shown after turning on or resetting the SALUS ST620 is a standard startup indicator. After a few seconds, the thermostat enters NORMAL mode and is ready to operate.

If the device is unresponsive:

  • Check and replace the batteries,
  • Ensure the keypad lock is turned off,
  • Perform a manual RESET using the reset button.

The ST620 can operate for up to 1 year on a single pair of batteries, and core data is protected by EEPROM memory, even after reset or power loss.