unvented hot waters cylinders are now widely recommended by plumbers as they offer many different benefits over the traditional vented copper hot water cylinders.
There are many benefits of an unvented hot water cylinders over a standard gravity hot water system such as.
- Frees up space in your home or loft
- Can be installed almost anywhere such as a garage
- Installed to the mains water supply for better water pressure
- No need to header tanks in a loft
- Pressurised heating system for better efficiency
- Can be installed to work with solar panels
- Perfect for flats or apartments where there is no loft
- Easy to maintain
- Reduced Noise
- Will not Freeze in winter
- Long manufacture guarantees
As a plumber of over 20 years, I have created this guide to give you all the information you need to compare volume capacity for the average three-bedroom house, below I go into more details about the five best unvented hot water cylinders.
Unvented cylinders take their water supply directly from the cold water mains, so there is no need to have a cold water storage tanks in the loft.
Another Benefit of an Unvented Hot water Cylinder
As unvented hot water cylinders are installed to the mains water, they can also be installed almost anywhere in your home or connecting garage.
If your airing cupboard backs onto a bathroom, you could now install an unvented hot water cylinder to the loft or garage freeing up space for that shower you have always wanted, without worrying about the water pressure.
Table of Contents
Are Unvented Hot Water Cylinders Safe?
Unvented hot water cylinders are mostly made from stainless steel, and they are designed to withstand sizeable internal force which makes them extremely safe
A qualified G3 unvented plumber should always install an unvented hot water cylinder.
Are Unvented Hot Water Cylinder Expensive To Run?
An unvented hot water cylinder is no more to run than a standard hot water system that you have a the moment as the cost is with the gas or oil boilers that you have.
If you have a standard economy seven or another electrically heated hot water system, the cost will most likely be the same
How Much Does It Cost To Install An Unvented Hot Water Cylinder?
I have broken the costs into a couple of different sections as there are several different prices depending on the type of installations and cost of the unvented hot water cylinder
So assuming you are removing the old hot and cold water tanks and installing the unvented hot water cylinder the place of the old hot water cylinder then the cost to install an unvented hot water cylinder will be between £500 and £1’000 plus the cost of the unvented hot water cylinder which will cost between £600 and £1’500
If you are moving the unvented hot water cylinder to another location in your home, then you should add between £300 and £500 on top of the price above to allow for extra pipework and labour, however, this will depend on how far you are moving the cylinder
If you already have an unvented hot water cylinder and you just need to replace it, then the cost will be much lower as the water supplies and discharge will already be in place
So you will be looking at a price between £300 and £500 plus the cost of the new unvented cylinder.
How Long Does It Take To Install An Unvented Hot Water Cylinder?
Changing over your water and heating system is usually not that difficult, and therefore an experienced plumber will change over a standard gravity feed water and heating system and install an unvented hot water cylinder within 2- 3 days however this can take longer depending on many different factors
The time to install an unvented hot water cylinder is dependent on a couple of different factors such as the type of existing system you have and its location
It can also depend on whether you are moving the unvented hot water cylinder to the loft or garage area; therefore, the time to install an unvented hot water cylinder can double
What Are The Different Types of Unvented Hot Water Cylinders?
There are two different types of unvented hot water cylinder these are direct and indirect
What Is A Indirect Unvented Hot Water Cylinder?
Direct unvented hot water cylinders are heating solely by an immersion heater within them and are an option for smaller homes, flats or apartments where you are unable to have a gas or oil boiler.
What Is A Indirect Unvented Hot Water Cylinder
Unlike a direct unvented hot water cylinder, an indirect hot water cylinder gets its heat indirectly so from a gas boiler, oil boiler or solar panels.
Some unvented cylinders also have an immersion heater as a second source of heat so that you can still heat your hot water if your boiler stops working.
How Long Should An Unvented Hot Water Cylinder Last?
Unvented hot waters cylinders are fairly simple however they are very efficient they are a large well-insulated steel cylinder with not a lot of part that can go wrong
This makes them easy to guarantee therefore you will find that most manufactures will offer lengthy warranties which can be ranging from 10 to 25 years
The guarantee for unvented hot water cylinders are that the stell cylinder will not leak and that all the manufactured outlets will not leak however what is not covered under warranty is the working parts such as
- Immersion heaters
- Pressure relief valve
- Temperature relief valve
- Copper pipework to the unvented cylinder
- Expansion vessel if not internal
This might look like an extensive list of parts that can go wrong however the parts are standard parts that can be easily got and be maintained
When purchasing any unvented cylinder for your home you need to know that they’re going to stand the test of time, this is why all cylinder comes with extended guarantees against any manufacturing defects should the worst happen.
Do Unvented Hot Water Cylinders Need Servicing?
Manufactures do recommend that you service an unvented hot water cylinder every 12 months by a qualified and competent plumber. In most instance, it could be a condition of the manufactures warranty.
How Much Does It Cost To Service An Unvented Hot Water Cylinder?
The cost for servicing an unvented hot water cylinder will be between £75 and £100 with places like London being the most expensive – the price given is an average price and will take around 1 to 2 hours to complete.
When servicing an unvented hot water cylinder, they should check the following
- Visually check the cylinder and parts
- Clean out the line strainer
- If external check expansion vessel is pressurised
- Check to make sure the pressure relief valve is working
- Check the temperature relief valve is working
- Make sure the tundish is not blocked and discharges ok
- Check the water temperature to make sure the thermostatic is working ok
Does An Unvented Hot Water Cylinder Work With An Electric Shower?
An unvented hot water cylinder works from cold water mains; therefore, this would not affect any electric shower you have already; therefore, all electric showers would work with an unvented hot water cylinder.
If you don’t already have an electric shower installed, then it might be best not to have one installed as a standard shower valve such as a bar mixer shower valve would work better.
Do You Still Need A Shower Pump With An Unvented Hot Water Cylinder?
As unvented hot water cylinders are connected directly to the mains water supply never install and shower pump to an unvented hot water cylinder and never install a shower pump onto the mains water supply
Shower pumps are connected directly to the hot water tank and cold water tanks Independently to any other water supplies in your home so that the flow rate to the shower is better and so that the hot and cold to the shower have equal pressures.
Shower pumps are designed to improve the flow rate of the cold and hot water to a shower or even multiple showers at once; therefore you don’t need a shower pump with an unvented hot water cylinder.
Five Best Unvented Hot Water Cylinders?
There are many different brands of unvented cylinders, we have done some research around the most popular brands of unvented hot water cylinders to help you make the right choice for your home.
Each cylinder compared will work directly with gas, oil or solar panels where solar panels are compatible and indirectly.
Heatrae Sadia - Megaflo Eco 125DD Direct Unvented Hot Water Cylinder 125l
- Capacity: 125 litres
- Cylinder Heating Type: direct
- Cylinder Type: Unvented
- Weight When Empty: 25KG
- Weight When Full: 165KG
- Cylinder ErP Rating: B
- Standing Loss: 39.2w
- Height: 1102mm
- Width: 592mm
- Depth: 579mm
The Megaflo Eco Direct Cylinder holds 125litres capacity of water, the first choice for conserving energy while providing superior hot water performance with a lifetime guarantee for total peace of mind.
Megaflo Eco Direct is unrivalled for hot water, delivering high-performance even if your water pressure is low.
Heatrae Sadia Megoflo Ecosystem Fit Indirect Unvented Cylinder
- Capacity: 210 litres
- Cylinder Heating Type: Indirect
- Cylinder Type: Unvented
- Weight When Empty: 69KG
- Weight When Full: 254KG
- Cylinder ErP Rating: B
- Standing Loss: 65W
- Height: 2053mm
- Width: 579mm
- Depth: 630mm
The Megaflo Ecosystem fit goes one step further than the standard Megaflo eco because the manufacturer has pre-installed the plumbing and wiring as a factory fit making it ready for installation.
Heat-only boiler – not only saves on installation time but will save you money because the plumber will not need to install that part of the pipework and wiring.
Gledhill Stainlesslite Slimline 180L Indirect Unvented Cylinder
- Capacity: 180 litres
- Cylinder Heating Type: Indirect
- Cylinder Type: Unvented
- Weight When Empty: 32KG
- Weight When Full: 197KG
- Height: 1791mm
- Width: 475mm
- Depth: 475mm
The Gledhill Indirect unvented cylinders are made by Gledhill.
This unvented cylinder has an incredibly fast heating time and as it is connected directly to the mains water wouldn’t have to wait too long to fill up a large bath this unvented cylinder provides outstanding levels of hot water performance.
This slimline indirect unvented model is compact and lightweight whcih enables this to be installed in smaller areas and can utilise the high efficiency corrugated tube coil which is to be connected to a standard boiler to heat the cylinder faster which is turn means faster recovery.
This unvented cylinder come complete with all the nessary compresstion fittings, lift up P&T valve, 90 degree hot water draw off.
Worcester Bosch Range Green Storage Unvented 210
- Capacity: 210 litres
- Cylinder Heating Type: Indirect
- Cylinder Type: Unvented
- Weight Empty: 50KG
- Cylinder ErP Rating: C
- Standard Loss: 2.304mm
- Height: 1496mm
- Width: 550mm
- Depth: 550mm
- Number of Immersions: 1
Worcester Bosch Range Green unvented cylinder, these cylinders are incredibly efficient due to the high level of heat retention to improve the overall performance.
Hence., if you’re looking for a highly efficient and high-quality cylinder, this is the one for you.
This cylinder has a FC/HCFC- free injected foam insulation benefiting from much-improved heat insulation.
Gledhill 90 Litre Stainless Lite Plus Slimline Indirect Unvented Cylinder
- Cylinder Capacity: 60 Litres
- Cylinder Heating Type: Indirect
- Cylinder Type: Unvented
- Cylinder Heat Loss: 28 watts
- Cylinder Height: 704mm
- Cylinder Overall diameter: 475mm
- Cylinder Number of immersions: 1
- Cylinder Weight (full): 75 Kg
- Cylinder Weight (empty): 16 Kg
- Cylinder Heat Up Time: 13
- Cylinder ErP Rating: A
The Gledhill stainless lite plus unvented hot water cylinder is designed for use with a gas or oil boiler.
This Gledhill unvented cylinder has a high-efficiency corrugated coil which maximises heat transfer to the cylinder which provides faster reheat times compared to a regular plain coil.
This unvented Hot Water cylinder uses 3kW Incoloy immersion heater for emergency back-up. This indirect heating system able to satisfy the hot water demands for 3 bathrooms and 3 separate shower rooms
