Greenvision Energy

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Unvented pressurised water cylinders

Talk to Greenvision - award-winning, national independent water cylinder installers

Why upgrade your old water cylinder to an unvented pressurised water cylinder?

Installing a low energy consumption hot water cylinder can significantly reduce your energy bill, improve bath filling times, increase shower pressure and increase and free up value space in your airing cupboard or bathroom as they can be installed in lofts, garages and utility rooms. Also, you may have a tank which is to big or to small, heating more water than you need or running out of water because the tank is too small.

Heating hot water can account for over 50% of your energy consumption so choosing the right hot water cylinder can save you £100s per year. We offer a range of low-energy consumption electric hot water cylinders for you or your business.

Our hot water cylinders are incredibly well insulated and have an extremely accurate thermostat which means less temperature variation. Less temperature variation means less energy used. They are also designed to take advantage of economy 7 tariffs & renewable energy sources and are complete silent.

We offer a free consultation to understand your requirements, we can guide you through different options, and answer any questions,  a free survey and hassle free installation service. Whether you are a homeowner, landlord or social housing provider sit back and relax with our award-wining installation service.  

We are Which Approved Installers and EDF Energy exclusively uses Greenvision for all their high heat retention storage heater installations.

The benefits of unvented water cylinders

Increased water pressure

Invigorating showers and quick filling baths are achieved with pressured hot water cylinders. We can remodel your airing cupboard to create more space.

Energy efficient lower energy bills

Pressure Cylinders have superior insulation and extremely accurate thermostats which means less temperature variation. Less temperature variation means less energy and cheaper bills.

Never run out water, multipe showers running

Lay back and relax and never run out of hot water again. Improve bath filling times and increase shower pressures. Now is the time to install a pressured hot water cylinder and start saving energy

Space saving and can be installed in lofts

A pressured hot water can be installed in lofts, garages utility rooms etc, freeing up valuable space in your airing cupboard and bathroom

Five things to consider when upgrading your water cylinder

Only company with plumbers that hold a G3 certification can install or maintain an unvented cylinder.

As with any major changes to your home it is vital to do plenty of research and talk to the experts about your requirements. 

Make sure you know what you want to get out of your new system. Greenvision will be able to offer advice on the best option for your needs and budget.

What type of cylinder should I install?

Think about your type of property and your requirements e.g. if you are in a mid floor flat with no loft access and your cylinder is positioned in the centre of your flat it may be difficult to install an unvented cylinder. A thermal store may be a better option as there is no need for additional pipework. Greenvision can advise on this.

Greenvision will guide you through the minefield of different heating options and answer any questions you may have. We believe knowledge is power and helps you make the right decisions. That's why one of the largest energy companies exclusively use Greenvision Energy for all of their electric heating solutions for their customers.

If you only have one bathroom, with just an electric shower you will only need a small cylinder or undersink heater that heats water at the point of use.

If the have multiple bathrooms and require two showers running at the same time with a drop in water pressure then a accumulator tanks are a good options. 

If you are using a shower running off your water cylinder, you need to bear in mind that a pressurised water cylinder can use up to 8-12 litres of water per minute. So a 120L cylinder can be drained very quickly. Greenvision can advise on your best options

If you have economy 7 tariff it is a good idea to have two heating elements on your cylinder. One connect to your economy 7 power supply for cheap low rate electricity and the other elements connect to your on-peak supply for boosting your hot water outside of your economy 7 times.

You might be able to free up valuable space by moving the cylinder into the loft or garage. If your cylinder is located in your bathroom and you are planning to remodel your bathroom it could be a good time to plan ahead.

What are my options when replacing old water cylinders

More Reasons To Buy Unvented Water Cylinders

Free up valuable space

If your cylinder is located in your bathroom or bedroom or you may have plans to remodel these rooms, you can relocate your new cylinder to a new location (loft or garage etc.)

Much faster heat up time.

Pressured hot water cylinder can produce fast efficient hot water very quickly. So, if you ever run out of hot water you don't have to wait long for a full tank of hot water

Reduced Noise Levels

No more waking up to cold water filling up the water storage cistern. The pressured system is completely silent and sealed, so not at risk of contamination and won’t freeze in winter months.

Hassle Free Installation

Invigorating showers and quick filling baths are achieved with pressured hot water cylinders. Be in control of your water temperatures to the exact degree. We can remodel your airing cupboard to create more space.

Sit back & relax with our award-winning installation service

Greenvision will manage every aspect of your installation. We remove and take away your old water cylinder, handle the cylinder delivery on the morning of installation and we will leave your property clean and tidy. Our fully qualified G3 engineers will show you how to get the best out of your new cylinder.

We are easy to do business with—no lengthy appointments and a quick quote within 24 hours. We’ll never try to pressure you into buying from us. Instead, we give you the information you need to make an informed decision. That’s why one of the largest energy companies in the UK, EDF Energy, trusts Greenvision to install electric heating solutions for their customers.
Start your free consultation today

FAQ's about hot water cylinders

Yes, Greenvision has a range of cylinders that you can control via a smart app.

With this type of cylinder there is no need for a storage tank as water comes straight into the cylinder via the water mains. Mains pressure means gravity feed does not apply, so the cylinder (minus storage tank) can be positioned virtually anywhere at any height, and you get a much more powerful flow than from a vented system. Also, you don’t have to worry about water freezing in a header tank during very cold snaps.

In an unvented installation the system won’t suffer contamination because it is sealed and bypasses areas were impurities could get into the water. With regards to water expansion, the unvented cylinder has either a permanent air bubble infused at the top of the cylinder, or a fitted expansion vessel.

Both vented and unvented hot water cylinders can use either direct or indirect heating systems. With the indirect method the cylinder is heated by a gas boiler or other external source. Hot water passes from the heat source through a copper coil built into the cylinder. In this case it’s a good idea to fit a reserve immersion heater in case of boiler breakdown, so you still have hot water.

The direct method involves one or two heating elements inside the cylinder that heat the water directly. Using the two element option can be very cost effective because it is specifically designed to be used with the Economy 7 tariff – one element for peak day time use and one for off peak where the water is heated cheaply at night and used when needed.

Vented hot water cylinders need a water storage (header) tank to store water piped in from the mains. The tank is usually installed in the loft (or in the highest point in the property) and the system relies on gravity to create a reasonable pressure for the hot water to circulate throughout the property.

Vented cylinders are easier to install than unvented, but they do need a vent pipe to deal with water expansion issues. Households most likely to benefit from vented water cylinders would be properties with an electric shower only, no bath and just one or two people living there.

You should only have an unvented hot water system fitted and serviced by a qualified person holding a current G3 Unvented Qualification. All installations of unvented hot water cylinders have to be notified to Building Control as required by Building Regulations. If your installer is a member of a Competent Persons Scheme, this will happen automatically and you will receive a Building Regulation Compliance certificate.

A hot water cylinder should last for more than 20 years if fitted correctly and to the highest standard. However, the life expectancy of a hot water cylinder can be shortened by water leaks.

They can be installed in almost any location – the garage, upstairs, downstairs, loft or even in a basement. An unvented hot water cylinder needs a safety discharge pipe. Therefore in some basement locations, a sump and pump may be required.

You should consider replacing your hot water cylinder if it is leaking water, but drying at the same time. Leaking water can get worse over time and cause damage. Small leaks can be hard to detect so you should always check for any damp patches surrounding a hot water cylinder. Consult your plumber or call Greenvision Energy if you are unsure about whether your hot water cylinder has a slow water leak.

  • If you get constant leaks or breakdowns it could work out cheaper to replace rather than to keep repairing. 
  • Your new boiler will be much more energy efficient and could pay for itself quite quickly. 
  • If you have a big family or use lots of water,  a new professionally fitted boiler will be sized correctly for your needs, which may not be the case at present. 
  • If you have an old boiler with a red jacket you will be paying higher energy bills than you need to. You would be better off upgrading to a new cylinder and better tariff. The off peak tariff in conjunction with the two element cylinder could save you lots of money. 
  • If your water pressure is low and it takes forever to run a bath or the shower is just a dribble, a new unvented hot water cylinder will give amazing improvements.

Need help? Not sure where to start?

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Water Cylinder Electric Unvented

What people think

Based on 33 reviews
Isobel Gleave
Isobel Gleave
I'm very pleased that I went ahead and replaced my old storage heaters with the new Dimplex ones. The whole process went smoothly and efficiently and Greenvision were very helpful at all stages and didn't rush me. Apart from working better than the old ones they also look smart, as does the new bedroom panel heaters. The installers did a brilliant job and didn't leave a trace.
Gemma Rogers
Gemma Rogers
Quality service for installation of a new Dimplex Quantum storage heater, Rointe electric towel rail, updated fuse box and all associated. The service provided by Greenvision went beyond all expectations. Everyone was extremely helpful and friendly. Stuart and Paul provided professional advice based on what would be best for me. The virtual survey option was ideal, so we could discuss options and get a quote straight away, which meant from contacting Greenvision to installation was only a couple of weeks! Amanda was great in keeping me up to date about the installation and arrangements. On the day, Dan arrived exactly when expected and fitted everything perfectly, it's made such a difference. Thank you to everyone at Greenvision. Very impressed and wouldn't hesitate to recommend!
Peter Graystone
Peter Graystone
I found Greenvision very pleasant to work with. The explanation of the product, and the survey to check it was suitable for my home were both excellent. The engineer was courteous and efficient, although I would have loved it if he had vacuumed before he left. I'm very pleased on the whole.
Purchase and installation of Dimplex Quantum Storage Heaters. Very professional from start to finish. In contact throughout. Answered questions and were friendly and helpful. Fitters were very efficient and even brought a hoover to clear up afterwards! They explained everything regarding usage. Very polite and professional from start to finish. Would recommend.
ann munro
ann munro
I instigated my business with Greenvision 6 weeks or so ago. The staff at Greenvision were informative, considerate of my needs and quick to answer any queries. Adjustments to my advantage were made after a survey which have proved to be most adequate. The installation occurred on 16th. January. The engineers were on time, efficient and considerate, clearing up and tidying up as they proceeded. They took time to make sure I understood the basics of operating my heaters. I will certainly recommend Greenvision where and when I can. So quick.
Sarah Moyer
Sarah Moyer
I used Greenvision for purchase and installation of 2 electrical high heat retention heaters for use with Economy 7. Everyone at Greenvision was friendly and helpful. Although based in Nottingham they facilitated installers for me in London. The whole process was seamless, quick and efficient. I would certainly recommend this company.
Carol G
Carol G
We purchased new Dimplex storage heaters through Greenvision. I was totally impressed by their level of knowledge, advice, customer service and ability to organise an efficient installation of these products at our property in North Wales. Highly recommended!
Lucy Reynolds
Lucy Reynolds
Very pleased with the installation of a Quantum Dimplex storage heater. Clearly explained at all stages and electrician who installed it was excellent.
Ray W
Ray W
6 Dimplex Quantum storage heaters installed to replace old heaters and associated modifications carried out to wiring in meter cupboard. Friendly helpful installers and very professional job. Highly recommended.
Brian Lomas
Brian Lomas
Supplied and fitted 3 Dimplex Quantum storage heaters. Used Greenvision because other residents in our retirement flats recommended them from their experience. They were right to do so as our experience was the same. From start to finish our experience was seamless and efficient ,polite, friendly are words that come to mind. The team that arrived with us on installation day was Nathan/Paul and Luker. All three were cleanly dressed, polite and friendly but courteous. They were very competent indeed and represented an excellent image of the Company. J B and L Lomas SANDBACH