I've an installation that has been working great for a few years now. But ... recently I've started to get errors with the Insteon on/off modules (2635-222) that I use with my landscape lights. 2 of 3 have decided they no longer want to work routinely. I replaced one of the two problematic modules and it doesn't wan to work either. I get an error message in the Indigo log that says "send failed no acknowledgement". I can repeatedly keep manually sending the on signal and sometimes it will then work, but mostly not.
Since I replaced one of the 2 problematic modules I'm not convinced that I suddenly have bad modules. But I will replace both again tomorrow with brand new modules and re-sync everything. Any suggestions on further troubleshooting I should do to locate and fix the problem?
I have ~20 other insteon modules that appear to be working fine. The 2 problem children are the 2 furthest from the Insteon control interface.