ROOM THERMOSTAT -NG21 – Stove ON/OFF Operation

Parameter Configuration

For the correct operation of the room thermostat for the NG21 control unit in ON/OFF mode, the technician must verify the following parameters:

Room Thermostat Input Check

It is possible to check the correct operation of the room thermostat from the remote control by following the path:

USER MENU → SERVICE → SECONDARY INFORMATION

Then access the item:

• IN9 → control unit input dedicated to the room thermostat

Operation Check

When activating the room thermostat, the value displayed on input IN9 must change:

• from 0 to 1
  or
• from 1 to 0

depending on the contact configuration.

This check allows verifying that the control unit correctly receives the room thermostat command.

False Contact Check

In case of anomalies or intermittent operation:

1. disconnect the wires of the room thermostat
2. check the value displayed on input IN9
3. verify if the value changes abnormally during thermostat activation

Possible causes:

• false contacts
• loose terminals
• damaged cable
• oxidized connections
• defective thermostat

Quick Test of IN9 Input

To directly verify the correct operation of the control unit input:

1. disconnect the room thermostat (usually located at the back; letter “T”)
2. make an electrical bridge on the thermostat terminals using a wire
3. check the value displayed on IN9

If the value changes correctly, the problem could be caused by:

• room thermostat
• wiring
• electrical connections

Technical Note

During tests:

• always perform checks with the stove in a safe state
• check proper tightening of terminals
• avoid unstable or temporary uninsulated connections
• restore the original configuration after testing