Unless your boiler has clearly stopped working the first thing you should establish is how old your boiler is. Most modern boilers have a healthy life span of around 20 years providing they have been regularly serviced. If it’s nearing this age then it may well be time for an upgrade. The key determining factor with ageing boilers is how well they function i.e are they economical? Around this age functionality can degrade quickly.
The moment you realise your boiler is no longer operating economically (meaning you’ll spend more and more on repairs, within shorter periods) you should definitely consider replacing it. We know that a replacement boiler is a substantial financial commitment for anyone and the decision to install one will not be taken without a lot of thought. However, it should be pointed out that a new and efficient boiler will save you approximately £300 every year; this is with the added bonus of your piece of mind!