Remember the golden rule: If the first secondary code doesn't work, keep going to 02, 03, or 05. If none of the 20 codes work, use IR Learning Mode.
Since this is an IR blaster, it needs a direct line of sight to the AC unit's receiver. remotec zxt-600 code list
Because the ZXT-600 is a "dumb" blaster. It uses the code list to send discrete commands (Temp Up, Fan Speed), but it does not have a feedback loop. Remember the golden rule: If the first secondary
If your brand isn’t listed (e.g., Hisense , Soleus , Koldfront ), try these: keep going to 02
Remotec stopped publishing an official PDF in 2018, but the codes are maintained via community databases.