Heat pump communication
If the Riello is not successfully communicating with the Passiv Smart Thermostat then check the following:
- Confirm the RS485 cable connections within the Riello indoor unit are the correct way around. If necessary double check continuity back to the previous device
- Confirm the screening drain wire is interconnected and earthed at a single point e.g. Programmer earth
- Ensure a single twisted pair (e.g. white core + black core) is used for A (white core) & B (black core). Do NOT double up cores or use cores from different twisted pairs for A & B connections
Heat pump operation
If the Riello heat pump fails to respond to changes on the Programmer or thermostats, such as a higher target temperature. Please check the Riello indoor unit for a failure code, often in new installations air may be present around the circulation pump, which may prevent the heat pump from starting.
Check MENU > FOR SERVICEMAN > ROOM THERMOSTAT, this must be set to NO. Setting this to any other setting will prevent the Passiv Smart Thermostat from controlling the heating.
For further guidance consult the Riello installation guide.