General Assist Technical Reference
ARTG LHTA Ducted Models – Return Air Sensor Offset
Adjusting the cooling and heating room-temperature correction by function setting
Applicable to ARTG ducted indoor-unit models ending in LHTA
Quick answer: Use Function 30 to offset cooling control and Function 31 to offset heating control. The available correction range is -1.0°C to +1.0°C.
Service personnel only: Function settings change how the indoor unit controls room temperature. Incorrect settings may result in poor comfort or abnormal operation. Record the original settings before making changes.
1. What the setting changes
The LHTA installation manual describes the available selections as Standard, Higher control, Slightly higher control, Slightly lower control and Lower control. The corresponding temperature correction values are shown below.
Cooling and heating are adjusted independently. Changing the cooling offset does not automatically change the heating offset.
2. Cooling return air sensor offset
| Setting description | Function No. | Setting No. | Temperature correction |
|---|---|---|---|
| Standard – factory setting | 30 | 00 | 0.0°C |
| Higher control | 30 | 01 | -1.0°C |
| Slightly higher control | 30 | 02 | -0.5°C |
| Slightly lower control | 30 | 03 | +0.5°C |
| Lower control | 30 | 04 | +1.0°C |
3. Heating return air sensor offset
| Setting description | Function No. | Setting No. | Temperature correction |
|---|---|---|---|
| Standard – factory setting | 31 | 00 | 0.0°C |
| Higher control | 31 | 01 | -1.0°C |
| Slightly higher control | 31 | 02 | -0.5°C |
| Slightly lower control | 31 | 03 | +0.5°C |
| Lower control | 31 | 04 | +1.0°C |
4. Entering the function setting using the UTY-RVNYN wired controller
Before starting: Stop the air conditioner. The function setting procedure must be completed while the system is not operating.
| 1 | From the Monitor screen, press the Menu button twice to open the Submenu screen. |
| 2 | Press and hold the left and right Screen Switch buttons together for 5 seconds. The Service screen will appear. |
| 3 | Use the up/down cursor buttons to select Function setting, then press Enter. |
| 4 | Select the R.C. address of the indoor unit being adjusted. For a single indoor unit, this is normally 00. |
| 5 | Move to Function No. and select 30 for cooling or 31 for heating. |
| 6 | Move to Setting No. and select the required value from 00 to 04. |
| 7 | Press Enter to save the setting. Repeat the process for the other operating mode where required. |
Controller timeout: The Service or Function Setting screen returns to the Submenu if no button is pressed for approximately one minute.
5. Recommended adjustment process
- Confirm that the return air sensor is being used as the room-temperature reference.
- Compare the return air temperature with a reliable thermometer positioned in a representative occupied area.
- Change only one step at a time: 0.5°C per step for settings 02 or 03, or 1.0°C for settings 01 or 04.
- Allow the system to operate and stabilise before assessing the result.
- Record the final cooling and heating function settings on the service report.
6. Example
Observed condition: The return air sensor requires a +0.5°C correction during cooling.
Required setting: Function 30, Setting 03 – Slightly lower control, +0.5°C correction.
This procedure applies to ARTG ducted indoor-unit models ending in LHTA and the UTY-RVNYN wired remote controller. Always confirm the exact indoor-unit model and controller type before changing function settings.