When it comes to installing central heating in your property, there are a number of options available to you regarding the type of boiler that can be installed. Not every property can have a gas boiler, nor is it always practical to have a oil or LPG boiler if you do not have the space outside for the storage tank. In these cases one of the only alternatives is the electric boiler. When buying an electric boiler they can come in various power outputs, and one of the questions we're often asked is 'what size boiler is needed?'
Sizes of Electric Boilers Available
It is important to choose an electric boiler for a central heating system that is the right size because if you buy one that is too small, then it will struggle to provide the heat and hot water that you need. On the other hand, buying a boiler that is too big will just be a waste of money.
One of the reasons why it can be confusing when looking at the power output of central heating boilers is the KW output of an electric boiler tends to be a lot lower than its gas counterpart. This is because gas boilers tend to be used in smaller properties that require a more conservatively sized central heating system. The electric boilers that we stock at Mr Central Heating generally have a max capacity of 12 kilowatt and up to around 60,000 BTU.
If you have water radiators (wet central heating) in your property and need to work out the capacity of a boiler to run them, then the rule of thumb is to allow 1.5kw per radiator. It's worth speaking to an installer to confirm this before you make an expensive mistake, but this guideline will allow you to get a rough idea of the costs involved. As you can see with a 12k kilowatt electric boiler you may be able to expect to run up seven or eight radiators on this size boiler. For smaller properties, this is likely to be fine. For flats and apartments you may even be able to get a smaller electric boiler. If you're considering electric central heating the secondary function of a boiler tends to be for water heating so this needs to be factored in too. A electric boiler that is being pushed to its limit may struggle to heat the property and provide an adequate hot water flow rate at the same time. It's possible to get secondary water heaters, but this might not be ideal.
Advantages & Disadvantages of an Electric Boiler
One of the reasons that electric boilers tend to be smaller is that the running costs are higher. Although electric combi boilers are highly efficient in terms of converting energy to heat, electricity is the most expensive fuel type. Types of boilers that use alternative fuel sources such as gas or oil are cheaper to run. Since larger boilers tend to mean higher energy bills, the boiler size for electric boiler types is generally smaller. For this reason, if you have a choice of boiler type then we do not normally go with an electric boiler primarily. It would be more beneficial to look at a gas combi boiler if you can, for example. Although all new boilers energy efficient, mains gas is much cheaper than electricity. In larger properties where heating and hot water demands are higher, you will really notice the difference. Unfortunately, gas is not available in all areas or can be very expensive to install.
On the plus side, electric boilers and electric heating are very efficient and will be effective for energy saving. In addition, the maintenance is much less than oil boilers, and generally, once they're installed they should be reliable for a long time. Often, they also take up a lot less space so can be very beneficial for smaller properties where space comes at a premium.
When looking at the right boiler for your property it is a good idea to to get a free quote from a heating engineer to work out exactly what you need and the associated installation costs. This way you can be sure that you have the best solution for your needs and an electric boiler system that will work for you.