Got up this morning, ran the hot water tap and couldn't get hot water, at this point my day started to go downhill. Central heating boiler problems are an absolute pain, always occur at the least convenient time and like many I rely totally on a combi boiler to provide heating and hot water so when it packs up I`m screwed. Boiler's only 18 months old, problem turned out to be the condensate drain line blocked solid with bloody ice. Fortunately it's v. easy to get to, with approx. 3 feet running vertically down the bungalow wall into a drain. 15 mins with a hair dryer fixed it and the boiler's now running OK again.



What I can`t work out is how to prevent this happening again, ideally the condensate line could've been run into the drain pipe from the dishwasher indoors, but now the kitchen's been refitted it's a sizeable job to modify so I`m stuck with the vertical pipe outside. Thought about lagging it but I`m not convinced it'll help, the temperature of the line follows the ambient cycle, warming above freezing (usually) in the daytime and dropping at night, if it's lagged it won't warm up as readily.

After a couple of days of sub-zero temperatures with no sunlight the line has blocked and I see no reason why it won't happen again, despite it being a simple problem to understand I`m struggling to find a solution.

If this was in an industrial setting the line would be trace heated and lagged, problem solved, I find domestic plumbing frustrating in this respect !.

All suggestions welcome. Modifying the line to make it easy to dismantle and allow the condensate to drip freely when the temp is sub-zero is one answer but it's hardly subtle.