My Gree AC is showing an H, E or F code — what do the common ones mean and which need a pro?

Gree does have a logic, and reading it first saves a wasted call-out. The first letter tells you the area: H = protection and status, E = pressure/protection, F = sensors, U = communication. A few of the most common ones and what they usually indicate: H1 is actually the unit DEFROSTING, which is normal, not a fault, so if it clears itself nothing is wrong; H3 is compressor overload protection; H5 is the power module (IPM) protecting itself; E1 is high-pressure protection; E2 is freeze protection; F1 and F2 are indoor sensor faults (ambient and evaporator). The honest caveat: exact meanings can vary by model, so your unit manual is the final authority on any code, and Gree's global support is where to match it to your exact model. On priority: many H-codes clear on a proper power-cycle (off at the isolator for a few minutes), and sensor faults (F-codes) are usually a straightforward component replacement, BUT E1 high pressure, H3 compressor overload and H5 power-module codes point at pressure, compressor or board problems and should stop you running it and get a professional, because running on those risks real damage. Same read-the-code-first logic as the Daikin and O General threads and the general error-code guide. If a protection code keeps returning after a restart, AC servicing in Dubai can read it on the tool and confirm. Photograph the code before you clear it.