1. Preparation
Before configuring indoor unit addresses:
Ensure that power to the system is OFF.
Confirm that the outdoor unit refrigerant address has already been assigned.
Decide on a logical addressing plan — for instance, by room, zone, or floor.
2. Understanding Indoor Unit Addressing
Each indoor unit (IU) connected to a refrigerant circuit requires two address settings:
Refrigerant Address (REF AD) — must match the outdoor unit it’s connected to.
Indoor Unit Address (IU AD) — must be unique within the same refrigerant circuit.
3. Setting the Refrigerant Address (REF AD)
The REF AD ensures each indoor unit communicates with the correct outdoor system.
Procedure
Locate the Indoor Unit Controller PCB.
Identify the rotary switches SW606 (REF AD x10) and SW607 (REF AD x1).
Set the refrigerant address to match the outdoor unit’s REF address.
| Example | REF AD x10 | REF AD x1 |
|---|---|---|
| 03 | 0 | 3 |
| 11 | 1 | 1 |
| 25 | 2 | 5 |
Important:
If the indoor unit’s REF address does not match the outdoor unit’s, communication will fail when the system is powered on.
Setting Range: 00–99
4. Setting the Indoor Unit Address (IU AD)
The IU AD gives each indoor unit its own identification number on the communication line.
Procedure
On the same PCB, locate the rotary switches:
SW604 (IU AD x10)
SW605 (IU AD x1)
Rotate each dial to the required position based on the assigned indoor unit address.
| Indoor Unit Address | IU AD x10 | IU AD x1 |
|---|---|---|
| 03 | 0 | 3 |
| 11 | 1 | 1 |
| 30 | 3 | 0 |
| 47 | 4 | 7 |
Address Range:
Valid: 00–63
Invalid: 64–99 (will not communicate with outdoor unit)
⚠️ Do not set any indoor unit within a system to the same IU address.
Each must have a unique address to avoid network conflicts.
5. Example Configuration
| Outdoor Unit | REF AD | Indoor Units (IU AD) |
|---|---|---|
| REF = 03 | 03 | IU = 00, 01, 02, 03, 04, 05, 06 |
| REF = 11 | 11 | IU = 00–63 (as required) |
In this setup:
All indoor units under the same outdoor circuit use REF AD = 03.
Each indoor unit is assigned a unique IU AD from 00 to 63.
6. RC Address (For Controllers)
The RC AD (SW608) is not required for modern two-wire controllers.
Only set the RC AD for older three-wire remotes, if applicable.
7. Address Restrictions and Communication Validation
If the indoor unit address is between 64–99, the outdoor unit will not recognize the IU.
After setting all rotary switches:
Power the system ON.
Confirm communication on the wired remote or via commissioning tool.
| Allowed Range | Communication Status |
|---|---|
| 00–63 | ✅ Normal operation |
| 64–99 | ❌ Not recognized |
8. Quick Reference Table
| Switch | Function | Setting Range |
|---|---|---|
| SW604 | IU AD x10 | 0–9 |
| SW605 | IU AD x1 | 0–9 |
| SW606 | REF AD x10 | 0–9 |
| SW607 | REF AD x1 | 0–9 |
| SW608 | RC AD (if applicable) | 0–9 |
9. Summary
✅ Key Points for Manual Indoor Unit Addressing
REF AD must match the outdoor unit.
IU AD must be unique within the refrigerant system.
IU AD range is 00–63 only.
RC AD is optional (legacy systems only).
Duplicate or invalid settings will result in communication errors and non-operation.