Well it was 1 of my concerns with putting the pellet stoves in. After talking here and to others thought we would be ok. Not. Sunday morning I went to use the sink in the upstairs bath only to be greeted with no water. Check of the bathtub had the same results. Fortunately none of the other bathrooms, sinks etc seemed to be affected. We go lucky though, turned the heat up a bit for the affected bath/bedroom (they are on their own zone) and I guess the heat produced enough warm air in the walls to free the clog. I guess the conditions Sat and Sat night/Sunday AM contributed to the problem as we had not had weather or temps like that since we put the stoves in almost 2 weeks ago. Conditions were: 9 above for a high Sat with high winds hitting the walls of the house were the affected bath was located. Sub 0 temps Sat night into Sunday AM. It was -22 when I got up Sunday morning. SO, I guess I need to put 1 of those thingy maggigys (tech term LOL) that you all were talking about. Thermo??????? Thanks for any info.