02/03/2018
In freezing weather if your condensing boiler stops working have look and see where the white plastic pipe coming out of the bottom of the boiler (condense drain) terminates. If it passes through the outside wall its most likely frozen up. If the boiler makes an unusual gurgling noise thats the condensate (water) building up in the combustion chamber, this normally flows out of the condense drain but not if its frozen up outside. You need to find a way of thawing out the pipe outside, various methods can be used, boiling water from kettle for instance.
Don't think that trace heating on the condense pipe will always work as I went to one yesterday which had frozen condensate. Customer said on the phone it was impossible unless the trace heater had stopped working. Unfortunately the installer terminated the pipe in a gutter, this had frozen solid as the down pipe for the gutter froze.
Cutting the condensate pipe and terminating in a bucket is a temporary fix but if you do disconnect the pipe you run the risk of allowing fumes to escape into the house. If the boiler has a suitable internal trap then this shouldn't be a problem, please be aware not all boilers have this.
Thanks