Gree GWH18AC-D3DNA1B Service Manual page 51

Troubleshooting
9.2.3.3 Diagnosis of high temperature overload protection (Check outdoor unit when cooling and indoor unit when heating)
Indoor unit display: H4 (dual-8 display), heating indicator is off for 3S and blinks 4 times.
Main detection points:
Is the indoor and outdoor ambient temperature in normal range?
Is the indoor and outdoor fan running normally?
Is the radiating environment of indoor and outdoor unit OK?
Is the indoor and outdoor pipe temperature sensor normal?
Malfunction diagnosis process:
4
8127 Fahrenheit
48