How to Replace a Boiler


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Check whether your boiler needs replacing and the potential savings you could make by visiting the British Gas’s calculator or the Energy Saving Trust website. Alternatively call British Gas on 0800 009 4450.
Consider having the boiler replaced during the summer season as opposed to the busy winter season.
Make a note of your existing boiler:
  • What is the make and model of your existing boiler? 
  • What is its energy rating?
  • Is there a flue for your existing boiler? 

Make a list of the following information before you approach any companies or start researching boilers:

  • How many people live in your home?
  • How often and how many people come to stay regularly?
  • How many radiators are in your property?
  • Do you have a separate hot water tank?
  • How many showers do you have? How many are thermostatic?

Make sure you know the pros and cons of a combi boiler which heats both the water and the heating and a conventional boiler which typically heats water separately using a hot and cold water tank. 

  Understand the importance of boiler maintenance to keep your boiler in the best condition.
  Check whether you can replace your boiler via the Green Deal and spread the cost of payment.
Check whether the Green Deal is right for you.
Secure three quotes to upgrade or fit a new boiler, ask for information about on-going boiler servicing.
Check the quotes to make sure you are comparing like with like, for example what is the hourly or day rate of the engineer? What is the comparable cost of the boiler, does the quote include VAT?
Find out what guarantees and for how long they are available for. Check whether the guarantees apply to both labour and parts 
Compare the cost of individual servicing and annual safety checks versus a monthly or annual boiler insurance cover such as British Gas Homecare and know what it covers, such as just the boiler or plumbing, drainage and even electrics.
Know how long you will be without heating and hot water for and how you will keep warm and heat water while the new boiler is being fitted.
Make sure anyone fitting the boiler is Gas Safe Registered.
Consider fitting thermostats on radiators at the same time as having a boiler fitted to reduce future heating costs further.


All our information is brought to you by Kate Faulkner OBE, author of Which? Property books and one of the UK's top property experts.
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