Hello all,
This could be the quickest and "BEST" Comcast replacement solution - this newer "SMC Brand" - in exchange for the current defective "Visonic Brand" !!!
Follow this URL link below for the SMC Brand CO Detector Specs and this would be a PERFECT replacement for us all !!!
http://na.smc.com/wp-content/uploads/2013/01/SMCCO02-Z-Datasheet-20130102-v1_2.pdf
Also, this newer SMC CO Detector is even more user friendly - and can pair up by us - then we just plug into a regular wall socket receptacle and Walla !!! 
The Comcast Central Station can also definitely Monitor this CO Device as well !!!
Come on Comcast - use your head here !!!
Jim