What is a conventional boiler?
Sometimes people call it a regular boiler. What it does is that it directly provides heat to the central heating system and then it produces hot water in your cylinder. These are very common in old flats and buildings especially in Europe and in the US. If you have an old-model boiler in your house, chances are you will be replacing it with a conventional boiler whenever you want to replace it. The hot water system is connected to an isolated hot water cylinder, while it also requires cold storage tank usually placed in the attic to feed the hot water cylinders.
Please see the video below which explains more about conventional boilers:
What is a combination boiler?
Normally called as “combi boiler”, it is a highly efficient water heater and functions as central heating at the same time. In short, it is a single compact unit that heats the water when you take a bath and heats your room to keep the temperature warm at night.
There is some more information on both conventional and combination boilers on the uswitch.com website.
Advantage and disadvantages
The best thing about combi boilers is that they are suited for homes with limited space. Usually, modern houses apply modular equipment to their homes to save space to provide enough mobility for people inside the house. Combi boilers are suited for couples living in apartments or small families who want to maximize the space in their humble abode. Aside from compact sizes, combi boilers do not require cold water tank storage and hot water cylinders. However, installation of this new model might be a bit expensive compared to the regular type. Usually, combi boilers are made of high-tech components which require higher maintenance cost.
On the other hand, regular boilers are commonly used in many households and buildings because they are much cheaper to install. One great benefit of using conventional boilers is that you can get hot water from several sources simultaneously without any pressure loss because of the large hot water storage. Regular boilers are suitable for buildings that use a lot of water and have enough space for its installation. It is also compatible with solar water heating systems and promotes low carbon footprint as well as low energy costs. However, you will have to install a hot water tank and cold water tank which eat up more space. Moreover, you always have to switch on the immersion heater to refill the water. Since you are storing hot water, considerable heat will be lost from the hot water cylinder.
In conclusion, both boilers offer advantages and disadvantages. The key to using the boiler suitable for your home is its use. Make sure to check your requirements before deciding which one to use.