My 220v dust collection system stopped responding to the X10 remote. After some investigation, including buying another remote device, but stopping short of trying to check line interference and other less-than-obvious issues, I saw a note on this forum that suggested rotating the dials on the appliance module to see if sawdust may have fouled the internal switches. I rotated the house code and unit code dials several times and this resolved the problem. (I now have a second remote which comes in handy). Thanks for the help!