On the left of the table above, you can see an energy efficiency rating. “G” is the very lowest rating any boiler can get for its energy efficiency rating. Did you know that many boilers that were state of the art ten years ago would perform badly in today’s tests? If your boiler is more than 15 years old, it almost certainly would fail a modern energy efficiency test completely.
The figures above are from the Energy Savings Trust. They show you the types of savings you can make every year on your heating bills by switching to a model A-rated boiler with thermostatic radiator controls, a modern programmer, and a room thermostat.
Let’s say that you live in a semi-detached house where your current boiler is F-rated. By switching to a new boiler, you’ll save up to £140 a year. If you replace your current combi boiler with a new one and no additional work is needed, it’ll cost you around £2,000. That means that your new boiler will pay for itself in 14 years.
What’s better? To spend £2,000 on a new boiler that will save you money or spend £2,000 over three to four years on a boiler that keeps breaking down and which doesn’t heat your home the way it used to?
What are the main types of boiler?
In the UK today, there are three main types of boilers, the most popular of which is the combination boiler. We’ll describe the differences between the boilers shortly but, below, you can see what it would cost, in most cases, to replace your existing boiler with a new one of the same type:
||In its current location
||In a new location
|Sealed system boiler
The Best Combi boilers provide heat on demand to deliver hot water to the taps and heat to the radiators. Compared with conventional and system boilers, they don’t require a separate water tank and, in terms of their overall footprint, they’re generally the smallest types of boiler on the market – great if your home is not the biggest.
Combi boilers are the most popular types of boiler in the UK but they struggle with power showers and providing hot water to more than one tap at any given time.
Sometimes called open vent boilers, heat-only boilers, regular, or traditional boilers, conventional boilers require space for a storage cylinder (for example, an airing cupboard or large utility room) and a water tank (generally located in a loft).
They take up far more room than combination boilers but, unlike combi boilers, they handle power showers well and they can distribute hot water at a high pressure to two or more taps at the same time.
Where they struggle is that, once the hot water has been used up, you’ll not have any more hot water until the storage cylinder is full again.
System boilers are even bigger and require more space than conventional boilers however they’re really only suitable for really large premises with lots of taps that require hot water at the same time.
As with a conventional boiler, you have to wait for the storage cylinder to heat more water up if it has been emptied through heavily family usage.
How big should my boiler be?
There are three main groupings of boiler according to size – 24-27kW, 28-34kW, and 35kW and above. Different types of property require different sized boilers and this table below will give you a good guide to the size you need for yours.
||Boiler size recommendation
||Boiler type recommendation
|1 or 2
|3 or 4
||1 or 2
||Combi or Conventional
The size of your boiler gives you an indication to how much hot water it can produce at any one time to provide to your radiators and your taps.
It’s important to get this right because if you or your installer choose a boiler which is too small, it will have ongoing problems providing you with the amount of water you need. You may suffer from real water pressure issues particularly if someone is running a bath and someone else is doing the washing up at the same time.
If you or your installer choose one which is too large, then hot water and heat will not be a problem. What will be negative for you and your family is that so much energy will be consumed keeping the boiler going that savings on your utility bills may be wiped out or you may end up paying more than you did before.
On most occasions, your installer will recommend that you do a straight swap to the same type of boiler in the same location as it is now. This will save you money and greatly reduce the time that installation takes. However, after speaking with you about how you use water, your installer may recommend a switch to a conventional boiler (or a system boiler if your home is particularly large).
What to do next?
You will be pleased to read that we have a vetted panel of reliable suppliers and installers of replacement boilers whom we can put you in touch with. They will be able to provide you with one or more free, no-obligation competitive quotes for your perusal.