Freezing cold weather can cause boiler condensate pipes to freeze, which can prevent the boiler from functioning.
How do you know if the condensate pipe is frozen? Your boiler may have started to make some unusual noises which normally you wouldn’t hear or shutdown altogether.
Is your boiler making this noise?
If your boiler is making a similar noise (almost like a choking noise) you can find out what to do by watching this YouTube video.
REMEMBER: use warm but not boiling water!