ARTG45LHTA - Error A1 and Heat Exchanger Refrigerant Leak
This article summarises the quality assurance investigation into an ARTG45LHTA indoor unit that displayed Error A1 and was found to have refrigerant leakage from the heat exchanger.
- Product: ARTG45LHTA
- Quantity: 1 unit
- Serial number: T001890
- Reported fault: Error A1
- Additional finding: Oil staining / trace of refrigerant oil at the heat exchanger
- Field pressure test: 3.5 MPa
- Leaks identified during field testing: 3 locations
Problem Description
Error A1 was reported on the ARTG45LHTA. During inspection, the technician identified traces of oil around the heat exchanger, indicating a possible refrigerant leak.
FG Australia carried out a pressure test at 3.5 MPa. Leak detection identified refrigerant leakage at three locations.
Factory Investigation
1. Factory Leak Test Process
The factory manufacturing test process was reviewed.
- The heat exchanger is charged with helium gas to 1.2 MPa.
- A leak detector is then used to inspect the assembly.
- The factory concluded that leakage of the type found on the returned sample would be detectable by the normal factory testing process.
2. Sink Test on Sample Unit
FGL carried out a sink test using the sample unit after charging it with helium gas to 1.2 MPa.
- Number of leaks identified: 5
- Leak location: Straight piping sections of the heat exchanger hairpins
- Visual finding: Black discolouration was present on the exterior of the hairpin tubing at the leak locations
Factory Cause Assessment
The factory considered that the leakage was most likely caused by external corrosion of the heat exchanger tubing.
- Corrosion appeared to have progressed from the outside of the hairpin tubing.
- The corrosion eventually penetrated the metal and created refrigerant leakage.
- The factory considered the installation / usage environment as a possible contributing factor.
Investigation Findings
| Check | Finding |
|---|---|
| Field pressure test | 3 leaks identified at 3.5 MPa |
| Factory helium sink test | 5 leaks identified at 1.2 MPa |
| Leak location | Straight sections of heat exchanger hairpin tubing |
| Visual condition | Black discolouration around the leaking hairpins |
| Likely mechanism | External metal corrosion progressing through the tubing wall |
| Confirmed root cause | Not determined |
Service Guidance
If a similar heat exchanger leak is found on an ARTG45LHTA:
- Record the unit model and serial number.
- Inspect the heat exchanger for oil staining or visible discolouration.
- Carry out leak testing using the approved service procedure.
- Record the exact leak location, including whether it is on a straight hairpin section, bend, joint or brazed connection.
- Photograph any blackening, corrosion, staining or other surface deterioration around the leak.
- Record details of the installation environment, including any possible exposure to corrosive contaminants.
- If multiple hairpin leaks or unusual corrosion are found, escalate the case with photos and site environment information.
Information Required for Similar Cases
The factory requested that any similar future cases be reported with detailed information about the installation environment.
- Indoor unit location and application
- Presence of chemicals, cleaning products or airborne contaminants
- Coastal or salt-air exposure where relevant
- High humidity or condensation conditions
- Nearby industrial processes
- Photos of the heat exchanger and leak locations
- Exact number and position of leaks