Combination boiler (Combi boilers)
Gas combi boilers are one of the most popular choices of boiler systems within UK homes, and with good reason. These compact heating systems combine powerful water heating and efficient central heating in one to provide households with on demand hot water and heat along with a plethora of other benefits.
Modern combination boilers are manufactured to double as a condensing boiler. This means they are able to capture some of the heat wasted from the gases and uses it to heat water returning from your central heating system. It's the perfect solution for saving on energy bills if you have an old non-condensing boiler. The only downside to combi boilers is that there can be a decline in water pressure if more than one person is using taps and they don't have backup immersion heaters in case of a break down.
The advantages that come with combi boilers are:
- They only heat the water you need when you need it.
- Safe water as it is fed directly from the mains and not stored in tanks.
- There's no need for any separate tanks or cylinders meaning more living space.
- Reduces your carbon dioxide footprint as there are less gases wasted due to it being a condensing boiler.
- Ensures fast delivery of hot water due to heat exchanger.
System Boiler
A gas system boiler is very similar to the conventional boiler set up, but with the majority of components that make up the standard heating and hot water system incorporated into the boiler system directly. The only additional storage you need is a hot water cylinder. The simple set up of gas system boilers allows for a quicker installation, much like the combination boiler, and results in a more cost effective central heating and hot water system.
System boilers warm up your home by using water from the mains supply. When you switch your heating on, the boiler will rapidly heat water from the mains supply and deliver it straight to your radiators. For domestic hot water, the water is heated in the hot water storage cylinder however it takes a while to do so. Once the water is heated though, multiple taps and showers can be used at once. Another downside to system products is they take up more space in your home than a combi boiler as you still need a cylinder.
The key advantages that come with system boilers are:
- System boilers include a pump, which means it responds quickly and has more economic running costs.
- Ideal for busy or larger households as the hot water cylinder is capable of storing large amounts of water and multiple taps can run without a drop in pressure.
- Built in components means installation is much easier than a standard boiler.
- Also compatible with solar panels.
Regular Boiler (Open Vent Boilers)
If you have a large tank of water in the loft and a hot water cylinder in an airing cupboard, then you have a regular boiler. They can often be referred to as heat only or conventional boilers too. A Regular boiler needs a large feed tank which is usually stored in an attic. This tank receives cold water from the mains and feeds it down to your boiler where it is heated for your radiators and to the storage cylinder which heats water for taps and showers.
An expansion water storage tank is also installed alongside the feed tank which helps to maintain a steady water level. It's definitely ideal for homeowners with a constant demand for water and multiple bathrooms such as a large family. Please note that regular gas boilers can take longer to install compared to the other gas boilers and they also take up a considerable amount of room. Pressure flow for showers and taps can be low as well but they still work even if your mains pressure is low.
The key advantages of open vent boilers are:
- Perfect for older homes in areas with low water pressure.
- Small leaks are generally not a large problem, and won’t cause a loss of pressure in your shower.
- Compatible with solar thermal systems.
- Installation is easy for homes with traditional heating systems.
