Well, early winter to be exact.
I live in an old house and over the last few years where we have suffered lower temperatures in the past (Global warming anyone?), I have always wondered why downstairs has a poor heat balance, even though I changed the positions of the radiators. The sitting room would be warm but the kitchen would be a tad chilly.
Over the last few years I’ve draught proofed just about everything in the house that could be draught proofed.
It wasn’t till I went to my daughters newly purchased house that I realised the elephant in the room. They had boarded up their fireplace.1
On getting home I held a sheet of the Guardian newspaper* against the fireplace opening and nearly had it ripped out of my grasp by the updraft. It’s a good thing I hadn’t given the job to an infant chimneysweep.
The upshot is that I bought a device like a balloon that you partially inflate, stuff it up the chimney and then fully inflate. It was noticeably different almost immediately. Everywhere is now warm quickly, with no draughts.
There was a couple of problems with the device, you need at least three hands to fit it and one more to hold the inflation tube.
You need to work how much partial inflation is required to begin with, otherwise it won’t go up the flue or it will fall out while you’re trying to blow it up to full pressure.
And you do need to check that it is not deflating, and pump up as required
However if we do get arctic conditions next week it will be removed, as there’s nothing better than sitting in front of a log fire.
* It was actually the Telegraph. The Guardian is only fit for emergency toilet paper.
1 And I call myself an engineer. 0/10 FAIL.