Can I use a combi boiler with a high-pressure water system?

Combi boilers have become increasingly popular in recent years as they offer a space-saving and cost-effective solution for heating and hot water in many homes. However, one question that often arises is whether a combi boiler can be used with a high-pressure water system. In this article, we’ll explore this question in more detail and provide some helpful information for homeowners.

First, it’s important to understand the difference between a combi boiler and a high-pressure water system. A combi boiler is a compact unit that provides both heating and hot water on demand. It works by heating water directly from the mains supply as and when it’s needed, rather than storing hot water in a tank. On the other hand, a high-pressure water system relies on a separate hot water cylinder to store hot water, which is then distributed around the home via a network of pipes and outlets.

So, can a combi boiler be used with a high-pressure water system? The answer is generally no. Combi boilers are designed to work with low to medium water pressure, typically ranging from 1 to 1.5 bar. This is because they use the mains water supply to heat the water, which can only provide a certain level of pressure. High-pressure water systems, on the other hand, require a minimum pressure of 2 bar, and can often reach pressures of 3-4 bar or higher.

Trying to connect a combi boiler to a high-pressure water system can lead to a range of problems, including a lack of hot water, low pressure, and even damage to the boiler itself. The two systems simply aren’t compatible with each other, and attempting to connect them is not recommended.

If you have a high-pressure water system and are looking for a new boiler, there are a few options available. One is to install a system boiler, which is similar to a combi boiler in that it doesn’t require a separate hot water cylinder. However, system boilers work with higher pressure systems and require a separate expansion vessel to accommodate the increased water pressure.

Another option is to install a regular boiler, which is connected to a separate hot water cylinder and works with a high-pressure system. Regular boilers are generally more expensive than combi or system boilers, but they can be a good option for homes with high hot water demands.

In summary, a combi boiler cannot be used with a high-pressure water system. Attempting to do so can cause a range of problems and is not recommended. If you have a high-pressure system, it’s best to consider a system or regular boiler instead, both of which are designed to work with higher pressure water systems. As always, it’s important to consult with a qualified heating engineer who can advise you on the best boiler option for your specific needs.