cynic wrote:

We had very severe frost last night so I enquired if there was an ice
plug in the condensate outlet. Neighbour got ladder out to look and it
turned out there was. Soon neighbour had kettle out and a warm house
soon after.
An hour later my phone rang and a friend told me he had no heat or hot
water. Jokingly I said it would be an ice plug in the condensate line.
Ten minutes later he phoned back to say it had been just that

I'm vaguely planning on replacing my (non-condensing) boiler in the next
few years. The condensate drain is definitely going inside!

Pete