I have the mrc 800 base and three remotes. They all worked for aa while. As of late none work. I made sure all have new batteries, all have been reset. I put them all together and they will comunicate when in close proximity to each other. When I put them in their respective locations they work for a while and them quite. All locations are within the 300 feet. One is only 30 feet away. I will attempt to get service help for this.