Different Boiler Types - Combi, Heat Only & System

Different Types of Boiler

No matter what type of boiler you have or are considering, it’s important to know the differences.

There are three different types of boilers for homes: combi boilers, system boilers, and heat only boilers (regular).

You’re going to learn what each one means, and the pros and cons of them. And remember, if your boiler stops working correctly, it’s always best to find an expert in heating and air repair in Atlanta who can help you.

Different Types of Boilers

Here are the main kinds of boilers, starting with the most popular:

1. Combi (Combination) Boilers

As its name suggests, a combi boiler equips you with both hot water and heating, all from one unit. It is typically hung on the wall.

A combi boiler uses a metal heat exchanger. This apparatus instantly heats water using gas or oil as a combustion source.

Combi boilers are largely energy efficient. Another advantage is that it heats both air and water, potentially saving you money on energy bills.

They are also relatively compact, so you can utilize them even in smaller homes. And since they connect to the water main, you don’t need to install a water tank.

However, combi boilers do not offer high water pressure. So if you have several bathrooms or otherwise large water demands, it may not meet your needs.

2. System Boilers

A system boiler, unlike a combi boiler, has its own hot water tank. Key parts of the boiler like the expansion vessel and pump are contained internally within the unit. That means an external cold water tank is not required. It receives the water from the mains.

The large hot water cylinder allows system boilers to be used in homes with high water demands. There are no attic components to install, so leaks and freezing are not a concern during colder months.

However, system boilers are dependent on the main water supply. If the water pressure is low, then you will experience a limited flow rate throughout the property as well.

The boiler itself has high water pressure, which may not be suitable for older heating systems.

3. Heat Only (Regular) Boilers

A regular boiler, also known as a “heat only” boiler, has three main parts: the boiler, a cold water tank, and a hot water tank.

This type of boiler provides hot water to a storage cylinder for hot water and also to your central heating unit for climate control.

Regular boilers work by sending hot water to your central heating system — which is essentially a radiator — and also to a hot water storage cylinder that provides hot water on demand throughout the home.

A cold water tank, usually situated in an attic, provides cold water to the boiler via gravity.

One of the main benefits of heat only boilers is the flow rate. If you have multiple bathrooms, then a regular boiler can meet increased hot water demand.

This is due to the boiler not requiring high pressure water from the mains. Heat only boilers are also friendly for older heating systems that can’t put up with the high pressures of closed systems.

In areas where there is lower water pressure, regular boilers are also advantageous. However, a traditional boiler might not work with newer heating systems. And you’ll need space to store the water tank.

Types of Boiler Systems — Which Is Best?

Ultimately, the best type of heating system for a home depends on a number of factors: the number of people living there, your peak usage demands, and the age of your home and water system.

In addition, there are key differences between boilers, furnaces, and water heaters. Your home might require one or all of these systems.

Read More: Boiler vs Furnace vs Water Heater

When deciding on the most reliable, powerful, and cost effective water heating method, it’s best to consult experts. Contact your local HVAC expert today and learn what your options are without the guesswork.