Thanks again for the replies. My alarm company set this system up so I will try and do my best to answer your questions. They have come out numerous times and have never fixed the problem. I am fed up with them and have since taken the job on myself.
The module I am using is I believe a universal module. It has two screws on it for contact wires and an on/off button to manually control whatever it is wired to (in my case a thermostat).
It looks a lot like this one, however, I don't think it has the two sliders on the bottom, but I could be mistaken. This module is plugged into an outlet, which happens to also be shared with my refrigerator. The system has always worked intermittently and now it just does not work at all. In an effort to find the problem, the alarm company that installed it has replaced the module several times, and I have purchased a boosterlinc from Smarthome. The alarm company has also replaced and upgraded my alarm panel.
How big is the cabin?
1200-1500 sq. ft.
How are you controlling your "a/c- heater with an appliance module?
It's a universal module, so when the system is not working, I turn the mudule on, then manually turn on/off the thermostat.
Have you added any electronics in the cabin since that time that the system worked?
No, as a matter of fact, I have unplugged all the appliances and still nothing.
Can you plug the BoosterLinc and Telephone responder into the same branch circuit as the appliance module? If this isn't possible, at least get the Boosterlinc and the Telephone responder on the same circuit.
Don't understand what you mean.
If you "unplugged everything in my house and still nothing" then it likely isn't a noise problem unless it is coming from a 240V appliance, or something new that is hard wired. If it isn't noise then a coupler / amplifier should help. You might also try the Smarthome signal level meter. It WILL tell you if it is noise and help you pinpoint the source.
I just purchased a coupler/repeater and plan on getting it installed this weekend. I will post the results.