There are many factors and options to consider when choosing which boiler is best suited to your requirements and your home. The type of property and usage are the key factors, but you will also need to consider the site of the boiler and your budget. The last thing you want is a boiler that doesn’t suit your home.

What kinds of boilers are available?

They come in all shapes and sizes, but which one is right for you?


  • Most likely to suit all households.
  • Ability to control both your central heating and hot water just from one unit.
  • Compact size, making it a good option for smaller properties.
  • No loft space needed in your home.
  • Installation can end up cheaper because there is less pipework involved.
  • Provides a constant flow of hot water from the mains.

System boilers:

  • Most suited to homes with more than one bathroom.
  • Doesn’t need a loft tank, which saves space.
  • No feed or expansion cistern makes them more efficient.
  • Offer a constant supply of hot water to any number of taps.

Conventional boilers:

  • Perfect for homes where a lot of hot water is used at the same time.
  • Suitable for large households with two or more bathrooms.
  • Requires a cold water storage tank in the loft as well as a hot water tank.

The most common boiler sizes:

24-25kw – suitable for flats and houses with 2-3 bedrooms, with up to 10 radiators.
28-30kw – suitable for 3-4 bedroom properties with up to 15 radiators.
33-35kw – suitable for large houses with up to 20 radiators.
40kw+ – suitable for larger properties with more than 20 radiators.

If you live in a small home with only one bathroom, or live on your own or with only one other person, a standard combi boiler without a hot water tank will usually be the best choice.

How long does an installation take?

In general, boiler installation may only take a day, assuming your chosen model is available. If it’s not an emergency boiler replacement, then try to replace your boiler before it gets too cold as there will be more availability.

When should I consider investing?

Unless you’re upgrading your boiler before a problem occurs, it’s likely you’ll be replacing an existing one because it’s not functioning correctly.

However, if you’re experiencing technical issues with your boiler, speak to one of our Gas Safe registered engineers who will be able to check it for you and see if it can be repaired. If this is not the case our engineers will be able to recommend the best type of boiler to replace it with, taking into consideration the size of your home and budget.