Can an Unvented Cylinder Freeze?

The ability to store and access hot water with the twist of a handle was nothing short of revolutionary. However, old-style vented cylinders suffered from many challenges that made life harder.

Unvented cylinders get around those issues, including being able to deal with cold temperatures much better. But can an unvented cylinder freeze? Let’s discuss what you need to know.

Why Did Vented Cylinders Freeze?

You might be wondering why a vented cylinder would freeze in the first place. There’s a combination of reasons behind this unwanted characteristic.

1. Installation Location – To be effective, vented cylinders had to be installed high up in the home, often in the attic where there was little protection from cold temperatures. This made them susceptible to freezing.

2. Cold-Water Tank – Unvented cylinders contain a cold-water tank that’s used to feed the hot water supply. When combined with the not-so-protected installation location, it wasn’t uncommon for these cylinders to freeze during the depths of winter.

Do unvented cylinders suffer from the same problems? No, they do not. The reason is their construction.

Understanding Unvented Cylinders

While vented and unvented cylinders technically perform the same tasks, they’re not really all that similar. Here’s how an unvented cylinder differs from a vented cylinder and why you don’t have to worry about them freezing:

1. Installation Location – Unvented cylinders can be installed anywhere in the home and they’re not limited to the uppermost floors. That means they’re better insulated from cold temperatures.

2. No Cold-Water Tank – Unlike vented cylinders, unvented cylinders are connected directly to the mains. Cold water flows in, is heated, and then flows out when needed. With no cold-water tank, unvented cylinders are much less susceptible to freezing.

3. Heat Sources – Unvented cylinders were usually heated by an external source, like a boiler. Unvented cylinders can be connected to the boiler, but they can also be configured to use an internal heat source (immersion heaters). Direct heating means a consistent internal temperature and no risk of freezing.

Freezing Mains

While unvented cylinders are virtually immune to freezing, that does not mean that cold temperatures won’t affect your access to hot water. Remember that your mains lines are outside the cylinder and are subject to freezing. Very cold temperatures can cause ice to form in the mains lines and create a blockage that will restrict your access to both hot and cold water.

Problems with Your Cylinder?

Are you tired of dealing with an aging, vented cylinder? Interested in learning more about how an unvented cylinder can benefit you and your family? Get in touch with the team at EasyFlow. We’re certified plumbers and authorised to install, maintain, and repair unvented cylinders.

We also offer a range of trusted brands from manufacturers you already know. We can help you determine the right unvented cylinder for your hot water needs and install it quickly. We’re also happy to troubleshoot any issues that you might have.