What is a Combi Boiler?
A combi boiler, also known as a combination boiler, is a heating system that provides hot water on demand. This type of boiler is designed to perform two functions: supply hot water and run your central heating through a single compact unit. The water supply comes directly from the mains and is heated within the combi boiler on demand.
There is no need for a cold-water supply tank or hot water cylinder. The water is supplied directly to the boiler and diverted to the tap or central heating. This offers space-saving efficiency but can also hinder its ability to handle multiple requests for hot water throughout a house.
The boiler functions with valves that operate in different directions. As a result, water can either flow into the central heating system or to a tap. It is not equipped for the demands of both. Multiple running taps and showers can also cause a drop in pressure/flow rate, preventing hot water from being delivered.
Depending on the size of the combi boiler, it may only be able to deal with one request for hot water at a time. However, larger, more powerful combi boilers could handle two showers. This means combi boilers aren’t suited to all homes, especially big houses or homes with high hot water demand.
The size of the combi is important and looking at the incoming flow rates into the property must always be checked. Some manufacturers also make more powerful boilers and storage combi boilers with multiple taps.
What is a Conventional Boiler?
Conventional Boilers are typically found in older or larger houses. This is due to the extra space required for separate components of the system. As part of the conventional boiler, a cold-water tank typically needs to be fitted into a loft space, and an airing cupboard is required for hot water storage.
A conventional boiler heats a large quantity of water at once and stores it in a hot water cylinder. When hot water is needed in the house or for central heating, there is a ready supply to meet the demand. In contrast, a combi boiler heats water only on demand.
This method is much more effective for properties with multiple bathrooms, requiring constant heating and hot water supplies. Of course, after a certain amount, the hot water supply will run out, and the system will need to be refilled to heat more water. If water is not heated in advance, you could be facing a thirty-minute or hour wait for a supply of hot water (dependent upon the amount required and the boiler’s specification).
