Boiler Heating System Types and How They Work

Boiler heating system is a fairly common type of HVAC system. Although it has been covered in previous articles, this article will help you to deepen your understanding and update your knowledge about the classification of boiler heating systems and how they are operated.

1. What is a boiler heating system?

A boiler sends hot water to radiators and water faucets. It both heats your home and provides hot water. This system combines the functions of a water heater and a furnace in one unit.

2. Types of boilers

There are three main types of boiler heating system: Combi, regular and system. Understanding the specification of each type can help you choose the right boiler that is suitable for your house.

2.1. Combi Boilers

A combi boiler contains two separate heat exchangers. Both are used to heat the water for the faucets and the radiators, respectively. There is no need for a hot water storage tank. The combination boiler combines a heating system with an on-demand or tankless water heater. In a combi system, the heating of the water is independent of the heating of the house.

The benefits of a combi boiler are:

Since you only utilize the hot water you require, you don’t needlessly heat an entire tank of water, which saves energy.
Another benefit is the effective use of available space. A combi boiler uses less space because it does not require the feed tank, expansion cistern, or hot water tank that are needed with some other types of boilers. Thus, it is fantastic if you reside in a tiny home or apartment.
A third benefit of the combi design is time efficiency: you don’t have to wait for the hot water in a tank to heat up. Because it comes directly from the mains, you can always have access to endless hot water.

2.2. Regular / Conventional Boilers

A regular boiler distributes hot water to your radiators and a hot water cylinder, often known as a hot water tank. A cold water storage tank called a feed tank, which must be situated above the cylinder and is typically found either in a cupboard or in the attic or loft space, supplies water by gravity into the cylinder.

conventional boiler system

Benefits of Regular Boilers

The device can provide water to many taps at once without the flow of water weakening, even in a busy residential environment.
For homes with solar panels, having a separate hot water tank makes solar thermal energy storage easier.

Regular boilers are frequently a sensible option for persons and families who need hot water more frequently, reside in larger homes, or have lower mains pressure.

2.3. System Boilers

A system boiler generates hot water by heating water directly from the mains, just like a combi boiler. But unlike a combi boiler, it doesn’t perform this function when needed.

Instead, hot water is instead kept in a hot water tank or cylinder for you to use as needed, much as with a standard boiler. The difference is that with a system boiler, heating takes place in the boiler itself, whereas it does with a conventional boiler in the tank or cylinder.

Families who are considering a conventional boiler and hot water system also have the option of a system boiler and hot water tank.

Benefits of System Boilers

One benefit of a system boiler is that it eliminates the need for a feed tank and an expansion cistern for the hot water tank.
Compatible with storage of solar thermal energy
Ideal for households with many bathrooms where multiple rooms are likely to utilize hot Water simultaneously
Less room is needed compared with conventional boilers;
Appropriate for buildings with a lower mains pressure

2.4. Condensing Boilers

A condensing boiler is a boiler with current heat exchanger technology that allows it to burn fuel more efficiently to heat your home. The heat created by some of the waste gases that would typically have been released into the atmosphere by your boiler is used by the heat exchanger technology. Condensing boilers typically have efficiency ratings that are much higher than those of older, less efficient boilers, which also means lower fuel costs.

3. How does a boiler heating system work?

A gas-powered boiler needs to be connected to the natural gas supply for a continuous source of fuel. It can also be connected to liquid petroleum gas cylinders that require regular refilling. When the thermostat triggers a heating cycle or you turn on the hot water faucet, a valve connected to the gas supply opens. The gas enters a sealed combustion chamber. An electronic igniter creates a spark or heats a filament that ignites the gas. Older boilers use a permanent pilot light to ignite the gas.

boiler heating system

4. Boiler vs Furnace

There is also a great deal of difference between the pros and cons of a boiler vs. a heater. Furnaces often cost less and take far less time to install than boiler systems. And, since furnaces don’t utilize water in the heating process, there’s less chance of freezing during a wintertime power outage. But the use of ductwork can create a drafty environment, and the spread of dust and dander is worse for families with allergies. Natural gas furnaces also run the risk of valve leaks, which can cause serious health issues.

>> Read more about electric heat furnaces

In contrast, the radiant heat from a boiler system is much more comfortable than forced air from a furnace. These units are also less noisy, more energy efficient, and create better air quality inside your home. No ductwork is required. In certain cases, the heated water from the system may also be used for things like laundry, showers, or your dishwasher. The downside to these systems is that they can be more expensive on initial installation, and if there is ever a leak the damage to your home could be quite extensive.

Again, choosing the right heating system for your home requires a bit of research and understanding of each system in comparison to your needs. In most cases, a boiler heating system is a better alternative, but there are both pros and cons of both types of units.