High efficiency condensing boilers will have a condense pipe going from the boiler to a drain of some description.
If this pipe becomes blocked then the boiler will stop working.
The condense pipe may become frozen or blocked by a backed up drain. It may be crushed or broken.
Any of the circumstances will lead to a boiler breakdown.
You may even hear a gurgling noise as your boiler fills up with water.
Because the condense pipework and trap form part of the boiler flue system you will need to call out a Gas Safe engineer.
If your pipework runs outside then ensure it is lagged/insulated to prevent it from freezing. If it does freeze then you can gentle thaw it out using warm (not boiling) water. then insulate it!
Check drains are clear and avoid pouring fat into you kitchen sink.
If in doubt just call us on 07428138282 and we will happily help you.