Hot Water Cylinder Guide To Unvented and Vented Cylinders

James Elston
Written by James Elston
Updated on 17th May 2024
Posted on 15th May 2024
Topic: Boiler Advice
Hot Water Cylinder Guide To Unvented and Vented Cylinders

Unvented Hot Water Cylinders and Open Vented Cylinder Comparison Guide

If you have a system boiler or regular boiler in your home, you will have a hot water cylinder that works alongside it.

This is basically a big insulated hot water storage tank that as you may have guessed, stores hot water waiting for your to use.

Many households depend on hot water cylinders to deliver hot water for daily tasks like showering, cleaning dishes, and doing the dreaded daily washing.

Get an online fixed price in 20 seconds:

What kind of fuel does your boiler use?

What types of hot water cylinders are there and which is best? 

In the UK there are two types of hot water tanks – Unvented cylinders and open vented cylinders. One is a sealed pressurised system and is better for modern central heating systems, whereas the other is not and is better for older systems.

Therefore, to assist you in selecting the best option for your household, we will evaluate and contrast the advantages of both types in this blog post.

Read more – changing from a boiler with a tank to a combi boiler

How we rank the best hot water cylinder:

Size, insulation, energy rating, and warranty come first on our list for choosing the best hot water cylinder. 

Along with how much hot water you use on a daily basis, these are the main factors that affect a hot water cylinder’s effectiveness and efficiency. To make sure that our ranking is relevant and accurate, we consider the needs and requirements of each potential different household.

Choosing the right size cylinder

We urge our customers to take into account the cylinder size when choosing a hot water heater because it needs to be able to provide enough hot water for the entire household as and when required.

A cylinder that is too tiny might not provide enough hot water, while a cylinder that is too large might use more energy than necessary and raise your energy costs.

Insulating a hot water tank

Insulation is another high priority for you in terms of energy efficiency as well because it prevents heat loss and keeps the water hot for longer. A properly insulated hot water cylinder can help save energy use and lower energy costs which is currently so important. 

Tank energy rating

Another important aspect to take into account is energy rating. To choose a hot water cylinder that runs effectively and doesn’t consume extra energy, we advise choosing one with a high energy rating. A cylinder with a higher energy rating is more energy-efficient and will use less energy to heat the water.

Warranty length

Finally, we stress the value of a strong and long warranty. A manufacturer’s warranty provides peace of mind and protection against any defects or problems. Having a longer warranty duration could mean that the manufacturer is more certain of the product’s quality.

Get an online fixed price in 20 seconds:

What kind of fuel does your boiler use?

Unvented Hot Water Cylinders

Unvented hot water cylinders heat water by drawing it straight from the mains via a system boiler.

These pressurised cylinders are a common option for contemporary homes because they don’t need a cold water tank. Unvented cylinders’ main benefits are:

  • More water pressure: Unvented cylinders provide a higher water pressure than open vented tanks, which makes showers stronger and fills water tanks more quickly.
  • Energy efficient: As unvented cylinders heat water directly from the main supply, they use less energy than open-ventilated tanks. This lessens energy wastage and heat loss.

Best Unvented Hot Water Cylinders on the Market

When it comes to choosing the best unvented hot water cylinder for your home, there are many options to choose from.

These excellent hot water tanks can deliver lots of hot water quickly as and when you need it at piping hot temperatures. Here are some of the top best hot water cylinder brands and models available on the market today:

Heatrae Sadia Megaflo Eco Plus

One of the most well known names in the unvented cylinder market is the Heatrae Sadia Megaflo Eco Plus.

This is one of the most popular unvented hot water cylinders on the market which comes with a lifetime warranty, high flow rates, and built-in electric immersion heaters. This high tech cylinder comes with a floating baffle expansion vessel within the unit ensuring that there is no need for additional sections.

Telford Tempest

Telford concentrate on making storage tanks, and the Telford Tempest is a premium-quality unvented hot water cylinder that offers fast reheat times and a high flow rate. It is made from high-grade stainless steel, which is resistant to corrosion and lasts longer than traditional copper cylinders.

Gledhill Stainless Lite Plus

Gledhill is another well-known cylinder brand. The Gledhill Stainless Lite Plus is a lightweight and energy-efficient unvented hot water cylinder that is perfect for smaller homes with lower hot water demands. Built to last, it is made from stainless steel and features a high-performance coil that heats water quickly and efficiently.

Vaillant uniSTOR

Vaillant is synonymous with heating in the UK, especially with their handmade boilers. The Vaillant uniSTOR is a versatile unvented hot water cylinder that is available in slimline, pre-plumbed, and standard models. Used best with a Vaillant system boiler, expect big things from this hot water cylinder as it comes with a 25-year warranty on the cylinder shell and a 2-year warranty on labour.

Get an online fixed price in 20 seconds:

What kind of fuel does your boiler use?

Open Vent Hot Water Cylinders

Open vent hot water cylinders are connected to a cold water storage tank in the loft or attic space. Used with conventional boilers, The water is heated by a boiler and then stored in the cylinder. The main advantages of open vented cylinders are:

  • Lower installation costs: Open vented cylinders are cheaper to install than unvented cylinders since they require a smaller and simpler setup.
  • Easy maintenance: Open vented cylinders are easy to maintain since they have fewer components and do not require pressure relief valves or expansion vessels.

Top Open Vent Hot Water Cylinders on the Market

Tempest Stainless by Heatrae Sadia

Another installment from Tempest, this product has a wide range of standard sizes, high-density foam insulation, and a 30-year warranty, making it the best choice overall for homeowners in the UK

Megaflo Eco by Heatrae Sadia

This is again a popular choice as an open vent system. The Megaflo boiler system offers a wide range of standard sizes, high-density foam insulation, and a 25-year warranty. Although it has a slightly lower warranty and energy rating compared to Tempest Stainless, it’s still a great option.

Tribune xE by Range (Kingspan)

This product offers a range of sizes and good insulation for efficient heating. It also has a 25-year warranty, making it a good choice.

Stainless Lite by Gledhill

This product offers a range of sizes and 50mm insulation, along with a 25-year warranty. Although it doesn’t offer as much insulation as some of the other products, it’s still a decent option.

High Gain/Standard by Gledhill

This product offers a range of sizes and 50mm insulation for energy efficiency, along with a 25-year warranty. It’s a good choice, but there are better options available.

Smart Cylinder by Mixergy

This product offers a range of sizes and 63mm insulation for efficient heating, but it’s relatively more expensive than other brands, which is why it’s ranked lower.

Premier Plus by Heatrae Sadia

Although this product offers a range of sizes and a 30-year warranty, its lower energy rating and insulation compared to other brands make it the least attractive option.

Get an online fixed price in 20 seconds:

What kind of fuel does your boiler use?

Unvented and Open Vent Hot Water Cylinders Comparison:

When comparing the two types of hot water cylinders, there are several factors to consider, including:

Performance

Compared to open vented tanks, unvented cylinders deliver higher water pressure while using less energy. Open vented tanks, on the other hand, are ideal for smaller families or those with reduced water demands.

Installation requirements

With expansion vessels and pressure release valves, unvented cylinders require more complicated installation. Simpler installation procedures and the need for a cold water storage tank are requirements for open vented tanks.

Maintenance costs

Given their complex setup and parts, unvented cylinders cost more to maintain. As they have fewer components, open vented tanks cost less to maintain.

Installation and Maintenance of Hot Water Cylinders

It is advised to contact a professional for hot water cylinder installation and maintenance. The cylinder must be connected to the boiler during installation, and all necessary insulation and safety precautions must be in place. Cleaning the cylinder, looking for leaks, and replacing parts as needed are all part of maintenance.

In conclusion

In conclusion, it is vital to choose the best hot water cylinder for your home in order to ensure that you have sufficient hot water while also keeping energy efficiency and low energy costs. 

Unvented and open vented tanks are the two types of hot water cylinders to take into account. While open vented tanks are less expensive to install and need less maintenance, unvented tanks are more energy-efficient and offer higher water pressure.

Factors for choosing the best hot water cylinder include its size, insulation, energy rating, and warranty. 

It is advised to select a cylinder with a size that accommodates the hot water needs of your household, good insulation to prevent heat loss, a high energy rating to reduce energy consumption, and a longer warranty period to ensure quality.

Get an online fixed price in 20 seconds:

What kind of fuel does your boiler use?
Written by
James Elston
James Elston Director Of Boiler Central
Posted on: 15th May 2024
Topic: Boiler Advice

James Elston is our resident boiler replacement and heating expert here at Boiler Central. With over 20 years experience in the boiler installation industry, James ensures that he knows everything there is about our Gas Safe boiler installations, energy saving and home heating solutions. This can be from simply procuring the latest best combi boilers, to reviewing and ensuring that Boiler Central maintains the highest standards across our boiler installation company.

Buy a new boiler in minutes

Instant online quotes. Nationwide next-day fitting

Get my fixed price
Get a great price on a Which? Best Buy boiler online in 20 seconds
  • Over 15,000 boiler installed
  • Rated Excellent on Trustpilot
  • Fair, fixed and final prices
  • No pushy salespeople
  • Next-day installation
  • 0% deposit interest-free finance
Next-day fitting available until 2pmGet a quote now >