
How to choose the right boiler for your home - jan 2023
How to choose the right boiler for your home
As a homeowner, replacing the central heating and hot water boiler often falls to the bottom of the priority list. After carrying out the myriad of ongoing repairs, decorating the kids’ room for the millionth time, or reconfiguring the living room according to the latest trends on Instagram or Pintrest, there’s always something else to spend time and money on. This means that we’re often ‘pushed’ into the boiler replacement pond, rather than jumping, which can lead to uncertainty over knowing how to choose the right boiler for your home.
Rapid Rundown 1: Boiler Types
Avoiding the realms of heat pumps and solar water heating, there are three main types of boilers that are installed in a domestic setting. It’s good to familiarise yourself with these in order to choose the right boiler.
Combi Boiler
These modern boilers provide hot water on demand for taps, showers, and baths, and also the hot water for your central heating. This type of boiler saves valuable space as it doesn’t require an additional storage tank which would need to be situated in a cupboard or loft space.
Heat Only (Conventional) Boiler
This is the more traditional boiler setup where cold water is heated and stored in a tank ahead of it needing to be used. These boilers may also utilise an additional storage or expansion tank often held in the loft of the property.
System Boiler
A system boiler works in a similar way to the conventional ‘heat only’ boiler, with an additional hot water storage tank. However, it does not require extra tanks held in loft spaces. External hardware such as pumps and valves are incorporated into the fabric of the boiler unit. These are the more up-to-date equivalent of a conventional boiler.
Rapid Rundown 2: Deciding Factors
Now you know the predominant boiler types, it’s time to learn what factors will influence the type of boiler that will be functional, as well as practical, for your property.
Property Size
It goes without saying that a larger property will require a larger boiler; that is to say one with greater heating capacity. Boiler capacities are measured in British Thermal Units (BTU) which is calculated as the amount of energy required to raise a pound of water by a single degree Fahrenheit. While it’s possible to determine the BTU requirement of your property based on things like number of windows and doors, building size and location, the general rule of thumb is that a domestic home in a colder environment will require 50 BTU per square foot. It’s important to get this right as an underpowered boiler will simply fail to heat your home and may overheat - not to mention waste lots of energy.
An easier way of thinking about this is how many radiators you have in your home.
Space
Closely linked to the size of the property is the space available for the boiler. Smaller properties, or shared accommodation such as flats (which will have a boiler per tenant) will have far less space for a boiler, limiting either the overall capacity of the boiler and associated tank installed, or constraining you to a simple combi boiler setup.
Current Setup
Consider your existing boiler. If you have separate water storage tanks, it may be simpler to stick with this type and retain this peripheral infrastructure. Switching to a combi boiler will do away with the additional tanks and connecting pipework, so removal and disposal of these will need to be factored into the conversion project.
Some properties may have a back boiler installed; these are fitted into chimney breasts behind appliances such as gas fires. After the introduction of the Building Regulations (2005), these can no longer be installed, so when it comes to replacing them one of the three boilers mentioned above will be used.
Demands
If you are likely to require large amounts of hot water and central heating at the same time, or if hot water may be used simultaneously at different outlets, a system boiler (one with an additional hot water reserve tank) may be a good solution. This is, of course, providing you have sufficient space.
Conversely, however, if there will be significant demand for hot water over an extended period (think Christmas period with multiple aunties requiring consecutive showers!) a combi boiler, which will technically never run out of hot water, may be the better choice.
It’s time to choose the right boiler!
So, you’re up to speed with the main types of boilers, and what you’ll need to consider to choose the right boiler. In the simplest terms, it’s a matter of deciding whether to opt for a combi boiler, conventional, or system, and then decide on the BTU capacity of the chosen system. But don’t worry, we are here to advise.
In most scenarios, where demands aren’t too great, switching to a combi boiler will be the optimal solution; they’re convenient with on-demand hot water, and free up cupboard space due to not requiring additional tanks. Owners can also enjoy lower maintenance costs as the integral heating and hot water functions are covered by the manufacturer's warranty.
Be aware, however, that combi boilers do not work well in properties with low water pressure; furthermore, the water pressure will drop if two outlets are used simultaneously, such as the kitchen tap and a shower or bath. Another consideration is the existing pipework; high performance boilers do not work well in conjunction with small gauge 15mm pipe and can be oversized for heating.
In situations where the property is particularly large, where there are significant demands for water, or the pressure is low, a system boiler may be a more suitable solution. Additional hardware such as pumps can be installed before showers to increase the flow rate, which is handy, however, will inevitably drain the hot water tank more quickly.
Other Influencing Factors to choose the right boiler…
The above factors are those that typically influence your choice of boiler purely on a practical and functional basis. There are other factors to consider, such as boiler efficiency and technical features (think wireless remote access, zoned thermostats, etc…). However, these are less determined by the property and demands, and more by your personal preferences.
If you’re still not sure or want help to choose the right boiler for your home, give us a call - we’d love to point you in the right direction and help you with your next boiler replacement project.