Our victorian toilet works perfectly normally BUT we have had minus 10 centigrade weather for over a week and we think the downpipe is frozen. That would explain why the toilet bowl overflowed when flushed. BUT we haven't used it since, we have emptied the bowl and thrown the water away down a different drain, and slowly but surely the bowl refills to overflowing. It is now thawing a bit but water expands with cold so why is water still coming into the bowl? :?