Hmm colder water won't effect the output from the boiler but if your worm is full of vapour and only just condensing then addition of cold water could be causing alot of vapour to collapse at once causing a sucking at the output temporarily halting the output.
The output from the worm should always be cool and if the temp starts rising it becomes dangerous. Possible explosion or fire from the alcohol vapour which is extremely hard or invisible to see!