
VENTED CYLINDERS
Vented cylinders provide a like-for-like replacement option for existing cylinders. We manufacture from copper to BS1566 standards, in grades 1, 2 or 3 thickness, dependent on application, with direct, indirect and combination configurations … to name just a few.
We stock a considerable range of standard vented hot water cylinders available for immediate dispatch or collection, and also offer a full bespoke design option where required.

Vented Cylinders

WHEELIflow
FREQUENTLY ASKED QUESTIONS
Vented cylinders are regarded as the traditional option, as they have been around for many years. They were first manufactured using copper due to the material’s efficient conductivity of heat.
Vented cylinders store and heat water that is fed directly from a cold feed tank in the loft, or from a combined header tank if no loft space is available.
The pressure of the hot water delivered from the vented is reliant on either the height of the cold feed tank above the cylinder or the addition of a pump on the hot water outlet to boost the pressure to the taps.
The main difference between a vented and unvented water storage cylinder is that a vented cylinder is supplied from a cold feed tank in the loft or an incorporated tank on top of the cylinder (combination type). These generally provide low pressure hot water.
An unvented hot water cylinder takes its water supply directly from the mains. You can get hot water out of an unvented cyinder at a much better pressure than a traditional vented cylinder as it is pressurised.
The grade (or thickness) of the copper vented cylinder is determined by the working head of the installation. The available grades of copper are;
- 1 – 25 metres (82 feet) maximum working head
- 2 – 15 metres (49 feet) maximum working head
- 3 – 10 metres (33 feet) maximum working head
Over the years, there have been many variations of vented cylinders installed in homes across the UK.
The most common vented cylinders are the direct (heated by immersion) or indirect (heated by a boiler utilising an internal coil). These are both fed from a cold feed tank in the loft. In apartments where there is no loft space available, then combination cylinders are used, holding the cold water directly above the hot water cylinder.
At McDonald water Storage, we are able to manufacture the more unique products such as Macmatics suitable for use with heating systems, twin cylinders to fit into small cupbard spaces, high performance and rapid reheat cylinders.
Vented hot water cylinders are dependent on the supply of cold water from a large tank which is located in the loft space. Also known as ‘gravity fed water systems’, vented cylinders rely on gravity and the elevation of the water tank for more powerful water pressure.
They are considered the most traditional means for household hot water production and are also a cheaper alternative to other hot water systems.
The main benefits of a vented cylinder include;
- A vented system is usually cheaper to install and requires lower maintenance than an unvented alternative
- If the mains water supply is cut off you will still have access to the tank of water in the loft.
Vented hot water systems are a way of heating up a large store of water for user delivery at outlets throughout a house. They also have the capacity to automatically feed more water into their system using a cold water feed tank above the hot water cylinder.
When cold water is heated up it expands and therefore needs somewhere to expand to. This is when the open vented system uses an expansion pipe back up to the cold water feed tank.
The cold feed tank should be of adequate size to feed the hot water cylinder. When any of the hot taps are opened in the house gravity will force the cold water into the bottom of the hot water cylinder for heating up and eventual use, forcing the hot water to the taps. The cold water supply tank is supplied by a mains pressure cold water feed that uses a ball valve to automatically keep the system topped-up, with an overflow pipe leading to a safe spot outside that is visible in case the expansion runs too much or the ball valve fails and doesn’t shut off.
The water in the cylinder is heated up by either the immersion heater of heating coil, the hot outlet pipe supplies the outlets (or taps) with the hot water supply. This pipe also tees off up to the expansion.
The immersion heater is usually seen as either the electric backup heater or in a direct model, the main heat source. With indirect models, the heating coil is used to transfer heat from heating system (from the boiler) to generate the hot water for the taps. Usually controlled by a programmer time switch and a thermostat on the cylinder.
McDonald Water Storage are the ONLY Company in the UK who manufacture all their Vented cylinders to BS1566 standards.
It’s a massive change in approach from the rest of the industry who largely manufacture to Part L of the Building Regulations, a lower grade of vented cylinder, which are purely designed and manufactured to meet the minimum standards required.
By ensuring our vented cylinders to BS1566 standards, we are providing units which adhere to strict quality standards regarding every aspect of the manufacturing process, from the thickness of copper material for the base and shell, to the length of coil in the cylinder.
This means that every vented cylinder which leaves our factory, is of a superior quality, more durable and more reliable than those which do not carry the Kitemark and are only made to part L.
Vented cylinders can start from as little as £180, but vary dramatically in cost dependent on volume, insulation, grade (thickness) of copper used, connection … the list goes on.
Vented hot water systems are a way of heating up a large store of water for user delivery at outlets throughout a house.
When any of the hot taps are opened in the house, the cold feed tank in the loft feeds the hot water cylinder, gravity will then force the cold water into the bottom of the hot water cylinder for heating up and eventual use, forcing the hot water to the taps.
The cold water supply tank is supplied by a mains pressure cold water feed that uses a ball valve to automatically keep the system topped-up, with an overflow pipe leading to a safe spot outside that is visible in case the expansion runs too much or the ball valve fails and doesn’t shut off.
The water in the cylinder is heated up by either the immersion heater of heating coil, the hot outlet pipe supplies the outlets (or taps) with the hot water supply.
The immersion heater is usually seen as either the electric backup heater or in a direct model, the main heat source. With indirect models, the heating coil is used to transfer heat from heating system (from the boiler) to generate the hot water for the taps. Usually controlled by a programmer time switch and a thermostat on the cylinder.