My door is no longer closing in the freezing weather and I have to pour hot water over the catch and then it closes again, I’ve sprayed wd40 dry ptfe on it but still does it. I can’t see from looking what’s actually happening. Never used to do this either. How can I fix?

2 hours ago, Jason87 said:

My door is no longer closing in the freezing weather ...

My door often displays this symptom in freezing weather, like you, the workaround is simply to pour hot water on it to unfreeze the locking mechanism. For the few days this happens in this country, I've never been bothered to find a permanent fix...

pouring water over it is the exact reason its playing up

the last thing you want on any of it, is moisture - its water freezing that is holding it from either unlatching and or re latching.  Instead you need lubricant on the linkages and the mechanism ....and that just got washed off with boiling water too...  when its as dry as you can manage, replace the remaining water with a suitable amount of lubricant in the right places and it will stop malfunctioning...

as for door seals NEVER pull hard, if really cold / stuck, light constant application of pull will help melt the ice and after a min or two it will pop open with no damage whatsoever... then you use silicon lubricant on all the door rubbers and ideally a little wipe of the grime around where the seal sit, so the now shiny bodywork also cleaned with a bit of silicon on a tissue as you go round, allows it to get a nice seal against the door.  Thus keeping grime out, moisture out, wind noise out and the door opening and closing as usual even during horrible cold snaps

1 hour ago, Botus said:

as for door seals NEVER pull hard, if really cold / stuck, light constant application of pull will help melt the ice and after a min or two it will pop open with no damage whatsoever... then you use silicon lubricant on all the door rubbers and ideally a little wipe of the grime around where the seal sit...

I do just that, however, for the actual catch you can only gain a very small access in the door jamb to spray a bit of lubricant inside it which does not solve the 'freezing' of it. You'd need to dismantle the lock from the door to properly apply grease to it, and if like me you can't be *rsed doing that, some hot water works just fine...