Vented & Unvented Hot Water Cylinders

Emergency Plumbers Bristol

Why Choose Watertite for Vented & Unvented Hot Water Cylinder Installation & Repair?

Whether you’ve got a vented or an unvented hot water cylinder, they’re essential to the performance of your boiler. In fact, without vented or unvented hot water cylinders, there’d be no hot water in your home at all.

Which is why if you’re only receiving an intermittent or no supply of hot water, the problem probably lies with your water cylinder.

But it’s important to know about the two different types of water cylinders – even if they’re not causing you any trouble.

Buying the right boiler for your home, and getting the best performance, is dependent on buying one with a cylinder that fits the needs of your household.

Choosing the right cylinder should be based on a few factors, such as the number of people in your household, how often and how long you use hot water, when you use it, and the overall cost needed.

But before we get to that, let’s answer a few burning questions first.

What’s the Difference Between Vented and Unvented Hot Water Cylinders?

Every type of boiler relies on cylinders to store hot water. The main difference is how these cylinders get their supply of water.

In a nutshell, vented cylinders require a cold water storage tank (often installed in a loft), while unvented cylinders get their supply directly from the cold mains water feed.

Vented cylinders need a pipe and a tank. These components work two ways: 1) water is heated within the tank so you can use it for your taps and showers; and 2) the vent pipe and tank can house expanding water when it is heated.

Unvented cylinders remove the middleman, so to speak, by connecting directly to the mains. It has built-in features that can accommodate excess water as it heats and expands.

Each cylinder comes with their own pros and cons:

Vented Water Cylinders
Advantages Disadvantages
Simple and cheap. Water pressure can be lower, as this type of cylinder relies on gravity. The more height there is between tank and shower means the pressure will be stronger.
You have a backup water supply in case your main supply is turned of Given that it relies on gravity, expect your shower and taps upstairs to have weaker pressure than that downstairs. Some households require an additional pump for better water pressure.
Requires almost no maintenance. Takes up more space, since you also need to install a cold water tank.


Unvented Water Cylinders
Advantages Disadvantages
Needs less space, giving you flexibility where you want it installed. Involves a more advanced technology, which means it would cost more for installation and maintenance.
Stronger water pressure. If your main supply is turned off, you won’t have a backup water supply.
Its sealed system removes the risk of contaminated water within the tank or frozen water during winter. Incompatibility with modern power showers and mixers.

Common Problems With Water Cylinders

At Watertite, we make sure your water cylinders are fixed effectively and efficiently. This begins with the proper diagnosis of your heating system.

You can find below the common problems with cylinders, so you can assess the severity of the situation. Do note that you should not attempt to fix these on your own to prevent more damage to your home and putting you (and your family) in danger.

Contact our qualified, Gas Safe registered plumbers immediately if you experience any of the following:

  • No hot water
  • Too hot water
  • Reduced water flow
  • Boiler switching on by itself
  • Fuse has blown
  • Valve is dripping more than normal (e.g. regular stream or gush)
  • Water discharged through the tundish
  • Discoloured or smelly water
  • System pressure loss
  • Strange noises coming from heating system

Play it safe, when it comes to your water cylinder. If you are unsure, call us so we can give you a full plumbing inspection and let you know what needs to be done.

Keep in mind that, no matter how reliable your cylinder is, you are still required by law to maintain them. The government’s BS2870 health and safety regulation, for instance, mandates unvented cylinders to be checked once a year by a qualified plumber.

Leave It To Bristol’s Plumbing Experts

If you’re installing a new boiler yourself or fixing a broken water cylinder – don’t. Unless you’re a qualified professional, this will only end up damaging your system more and put you in danger.

At Watertite Plumbing & Heating Ltd, our clients are family. We always aim to solve any problem as soon as we can, with as little disruption your lives as possible.

All you need to do is call, and we’ll do the rest.

Our team of professional plumbers are Gas Safe registered, with years of experience under our belts. We can give you a proper diagnosis, sound advice, and high-quality service.

Hot water is often taken for granted, especially when it’s always there when you need it.

If your hot water has dissipated, call us for an immediate response at 01179 093 967 and we’ll be with you as soon as possible.