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XII.
PROTECTIONS AND ALARMS
In order to ensure safe and failure-free operation, the regulator has been equipped with a range of protections. In case of an
alarm, a sound signal is activated and the display shows a message informing about the detected problem.
Type of alarm
Possible cause
How to fix it
Alarms with actuators STT-868
Actuator alarm - ERROR #0 -
low battery level
Flat battery in the actuator
Replace the batteries
Actuator alarm - ERROR #1 –
possible damage of mechanical
or electronic parts
Some parts have been damaged
Call the service staff
Actuator alarm - ERROR#2 – the
maximum actuator stroke has
been exceeded
- No piston controlling the valve
- Too big stroke (movement) of
the valve
- The actuator has been
incorrectly mounted on the
radiator
- Inappropriate valve on the
radiator
- Install a piston controlling the actuator
- Check the valve stroke
- Install the actuator correctly
- Replace the valve on the radiator
Actuator alarm - ERROR#3 – too
little piston movement
- The valve got stuck
- Inappropriate valve on the
radiator
- Too little stroke (movement) of
the valve
- Inspect the valve operation
- Replace the valve on the radiator
- Check the valve stroke
Actuator alarm - ERROR #4 – no
return communication (to the
actuator)
- Out of range
- No batteries
- The actuator i stoo far from the
controller
- Insert batteries into the actuator
After the communication is re-established,
the alarm is deactivated automatically
Alarms with actuators STT-869
Error #1 - Calibration error 1 –
Moving the screw to the
mounting position took too
much time
- The limit switch sensor is
damaged
- Call the service staff
Error #2 - Calibration error 2 –
The screw is maximally pulled
out. No resistance while pulling
out
- The actuator has not been screwed
to the valve or has not been screwed
completely
- The valve stroke is too big or the
valve dimensions are not typical
- Actuator current sensor is damaged
- Check if the controller has been installed
properly
- Replace the batteries
- Call the service staff
