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Nova DC connection kit

Part number: C545K

Description​

Nova climate control kit using a direct DC power connection to the 10″ Nova wall controller. Includes COCBH Smart Hub for iZone Home app connectivity. The controller communicates wirelessly via the Smart Hub.

Installation guide​

🧭ONLINE GUIDENova Installer Training Course→▶VIDEOGeneral installation videoVIDEO→▶VIDEONova with DC power — zone temperature sensorsVIDEO→▶VIDEOConnecting Nova to the internetVIDEO→▶VIDEOPairing wireless temperature sensorsVIDEO→📐WIRING DIAGRAMC545K wiring diagramWIRING→

Specifications​

EntryDescription
CPUC225
Power supply24VAC 50Hz via CT24ACE
Wall controllerCCASLW — 10″ Nova touch screen (DC)
CommunicationsWired CAN Bus · Wireless 433MHz (iZone proprietary)
Number of zones0 to 8 (expandable to 14 with CEXT)

Included in​

Part numberDescription
C2258-zone CPU
CT24ACE24VAC power supply
C325#AC unit interface module — brand specific
COCBHSmart Hub
CCASLWNova wall controller — 10″ touch screen (DC)
CTDC12Nova DC power supply
CDTSIn-duct temperature sensor (required if using zone temperature sensors)
C546K
Nova CAT kit
C536K
Nova Mini CAT kit
C535K
Nova Mini DC kit
C225
8-zone CPU
COCBH
Smart Hub

Documents​

📄DOCUMENTC545K Installation ManualPDF→📐WIRING DIAGRAMC545K Wiring DiagramWIRING→

Troubleshoot guide​

Read more

Nova wall controller screen is blank or unresponsive

The Nova or Nova Mini touch screen fails to power on or goes black.

Steps to resolve:

  1. Check the power supply (CTDC12) connection to the Nova wall controller
  2. Check the Cat5e cable between the CSL Screen Link Module and the Nova — try a different port on the CSL
  3. Re-pair the CSL to the C225 CPU if the connection has been lost
  4. Replace the cable if the issue persists
  5. If still unresolved, contact your installer — the CSL or C225 CPU may need to be replaced

Zones are not opening or responding

One or more zones are unresponsive when commanded from the Nova wall controller.

Steps to resolve:

  1. Move the zone motor cable to a different port on the C225
  2. In the Nova app, go to Setup → Configure AC → Options → Skip Zone Port (password: wamfud) and skip the faulty port
  3. Verify the CT24ACE transformer is powered and outputting ~24VAC
  4. Check all wiring connections are fully seated

Note: On Daikin systems, it can take up to two minutes for dampers to open after a command is sent.

Nova controller not communicating with C225 CPU

The Nova wall controller shows no connection to the system.

Steps to resolve:

  1. Confirm the COCBH Smart Hub is powered and the Nova shows the Wi-Fi symbol
  2. Re-pair the CSL to the C225 if pairing has been lost
  3. Ensure the Smart Hub was not connected to the internet modem before commissioning was completed — if it was, disconnect it, factory reset the COCBH, and recommission the system
  4. Add a repeater (CR) if the Smart Hub is out of range of the C225

Temperature sensor not showing actual temperature

A zone shows no temperature reading despite having a sensor fitted.

Steps to resolve:

  1. Press the button on the sensor — if no lights appear, the battery needs replacing (CR2032)
  2. If the sensor flashes instead of showing solid red or blue, it needs re-pairing: press and hold the pair button, then pair through Menu → Devices in the iZone app
  3. Ensure the CDTS in-duct sensor is installed upstream of all dampers in the supply air duct
  4. Check the sensor is not obstructed by furniture or exposed to direct sunlight

Firmware history​

No firmware history — this part contains no embedded software.