Most expensive doesn't always mean most performance. Here, we'll dive in to the biggest factors you should consider when buying a new boiler for your 3 bedroom house. Enjoy.
Do you live in a 3 bedroom house and are curious to know which boiler is the right choice?
For most people a modern combi boiler will be the best option, hence why it’s the most popular type of boiler in the UK.
However, depending on your home’s hot water demands a heat only or system boiler may be more appropriate.
So, let’s uncover which is the best boiler for your 3 bedroom house…
Is a combi boiler the best choice for your 3 bedroom home?
A combi boiler or combination boiler provides both heating and hot water on demand from a single wall-mounted unit.
They take their water directly from the mains water supply and modern A-rated models are extremely efficient.
For the majority of 3 bedroom homes, a combi boiler will perform amazingly well at meeting your home's heating and hot water requirements.
The average 3-bedroom home will require around 4-10 kW per day depending on how well the property is insulated.
Combi boilers are offered in a range of sizes or power outputs ranging from 24 kW to 54 kW, however, this is for hot water. For heating, combi boilers offer much lower heat outputs of around 18 kW.
This means that if you have multiple bathrooms in your home that are likely to be used simultaneously, a combi boiler may struggle to maintain a good supply of hot water to both outlets.
In addition, if you have more than 3 bedrooms and therefore more radiators than average, a combi boiler may struggle to maintain adequate heating.
Does your home have a high hot water demand (multiple bathrooms)? You may want to dodge a combi.
There are other situations where a combi boiler may not be appropriate, but these are less common. They include low mains water pressure, as well as incompatible pipework.
In any of these scenarios, either a system or regular (heat only) boiler would be more appropriate.
Sizing a combi boiler for your 3-bedroom home
To determine what size boiler you require for your home i.e. what power output (in kW), you can use this formula for an estimation:
1 kW for small radiators or towel radiators
1. 5 kW for an average-sized radiator
2 kW for a large radiator
Using the above scores and the number of radiators in your home, add them all together to determine the total kW required.
You can read our full guide on “what size boiler do I need?” for more in-depth guidance and information, or use our quick tool to determine the exact boiler that’s best for your home.
Best combi boilers for your 3-bedroom home
To determine which are the best boilers available, we considered the following factors:
Warranty period offered by the brand
The overall reputation of the brand based on customer reviews
Trustpilot reviews
Awards and accolades e.g. Which? Best Buy Awards
Customer service performance
The price range of their boilers
Efficiency ratings
The cost of a boiler doesn’t always necessarily mean it’s better either, so we have included some brands that are considered “budget-friendly”, yet are still technically brilliant.
You can read our comprehensive guide in which we rank the best boiler manufacturers here.
Best combi boilers for smaller homes:
#1 - Viessmann Vitodens 100-W 26kW
#2 - Baxi 600 – 24kW / 30kW
Best condensing boilers for larger homes:
#1 - Viessmann Vitodens 100-W 35kW
#2 - Worcester CDi Classic 38kW
Best offensively large, powerful combi boilers:
#1 - Worcester CDi Highflow 44kW / 55kW
#2 - Viessmann 111-W 35kW
Is a system or regular boiler better for your 3-bedroom home?
As mentioned, if your home has a high hot water demand, a combi boiler may not be able to keep up with the demands, in which case a regular (heat only) or system boiler will be more appropriate.
System and regular boilers both have someting in common, a separate hot water cylinder.
The boiler supplies hot water to the central heating, while the storage cylinder provides the hot water.
The storage cylinder is where the hot water is kept before use, since it offers a considerable reserve of hot water, it is more appropriate for situations where two or more water outlets may be being used at the same time.
They also have the backup of an immersion heater, which is great.
Sizing a system or regular (heat only) boiler
The average 3-bedroom property will require between 4-10 kW a day depending on the age of the property and the level of insulation.
System and storage boilers are offered in a range of different sizes (power outputs) starting at 11 kW, which is sufficient for most homes of this size.
The size of the hot water storage cylinder is another important consideration. Most storage cylinders are heated via an internal metallic coil.
The coil itself has its own power capacity measured in kW that it requires from the boiler to heat the water in a reasonable length of time, which is referred to as the hot water recovery time.
So similar to a combi boiler, to determine the size boiler you require, use the following formula:
1 kW for small radiators or towel radiators
1. 5 kW for an average-sized radiator
2 kW for a large radiator
Using the above scores and the number of radiators in your home, add them all together to determine the total kW required. Then add 3 kW to account for your hot water storage cylinder.
Related boiler guides:
The Viessmann 111 - The Hybrid Solution
The Viessmann Vitodens 111-W is one of the brand's most notable innovations - a storage combi hybrid that is able to meet the high hot water demands of any modern family home, without the need for a separate hot water storage cylinder.
The boiler is relatively large and is certainly larger than the average-size combi boiler, but if you do want to save space and avoid the need to house a separate cylinder it still offers an advantage.
Internally, the Viessmann 111 includes a combi boiler on one side, offering 35 kW of central heating power, and a hot water boiler on the other, offering 35 kW of hot water performance.
So if you are looking for a boiler that can meet your home's high demand for hot water, but don’t have the room to house a separate storage cylinder, the vitodens 111-W may just be the best boiler for you and your family.
It offers you the ability to run between two to three showers at once, up to a maximum of 18 litres per minute.
What happens if you choose the wrong size boiler?
If you under spec your boiler...
In the case of combi boilers, selecting a combi boiler that is too small i.e. has a lower heat output than your home requires is not typically an issue.
...why?
The majority of combi boilers are designed to heat up to around 14 to 20 radiators.
The issue is typically going to arise from the boiler not being able to meet your hot water demands, therefore, it’s important to ensure the combi boiler heat output matches your cold water flow rate.
If you over spec your boiler...
If you choose a boiler that is too large for your home i.e. the heat output, then this generally isn’t an issue.
...why?
Newer boilers have something referred to as modulation.
In basic terms, this means that the boiler reads some sensors and is able to adapt e.g. by reducing the heat output if it senses a lower demand.
Get A New Boiler Quote Today
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