Same problem, no solution :(
I've bought two Sonoff RF units with remotes. Both connect to WiFi ok, BUT neither pair with 433MHz remote using instructions provided. ie. press button twice rapidly to place in pairing mode. No red LED and no pairing. I tried pressing button on RF board for 2 sec (as per post by Mike), but still no result. I note there has been no response from ITEAD - this is very frustrating!! I have attached a photo of the unit I have. CAN SOMEONE FROM ITEAD PLEASE RESPOND.
I have the same problems with 2 sonoff RF, Its nor pair at all, with the original remote that sale in Itead
You need to click very quickly 2 times to write. 3 times to erase from memory.
I believe we know all the procedure now.
Receivers do not work.
I tried with 5 different remote controls but nothing.
And iteadstudio continues to not respond.
It does not seem to me to behave correctly.
I tried 5 different.
The remote controls work perfectly with the 4ch pro but are ignored by RF.
You need to know what remote control are compatible, or how to install a compatible receiver so you can use a single remote control. Externally they all look the same.