[I don't remember why it's set to C - at first it was set to housecode B. Since it wasna't working, I thought that it might be interfering with the transceiver.
The house code that is set to Monitored is just for use in macro conditions. But a
Walt2 suggested, make sure B is the CM15A's Transcieved house code and remove the 2nd Transceiver.
For more info on the difference, please read this topic:
What's The Difference Between Monitored and Transceived HouseCodes?I don't have a clear understanding of the relative priority in these modules - does the CM15A outrank the transceivers? Do they conflict with each other if you have one of each set to the same housecode?
No transceiver out ranks the other, but some are polite and others are not. For reliability purposes, never have the same house code Transceived by more the one unit.
The AHP display on my PC has no effect on the lights. The CM15A is about 8 feet away from the B1-B3 switches and 15 feet from lamp module B13 (2 interior walls).
The physical distance between the CM15A and the modules is not what matters here; what matters is the electrical path between the two. If the CM15A will not control a module, then there is some electrical issue on that path. These issues are generally a Noise Source or an X10 Signal Sucker. There is most likely some electrical items in your house plugged into the circuit(s) that the CM15A and/or the modules are on.
You can move the CM15A around to try and find the best location for it to work, but I suggest you
map out the electrical circuits and the phase each of them are on.
It can take a bit of effort & lots reading to get a system to work reliably, but in the end it will be worth it. For more information on Noise Sources and Signal Suckers do a search and check out
JeffVolp's Powerline Control Reliability section of the forum.