Need a hot
water Cylinder
installed?
We’re fully qualified to install, service
with and repair Unvented Cylinders.
Unvented hot water
systems
These systems have no cold-water storage tank
In an unvented system, there’s no need for a coldwater tank; instead, a sealed hot water cylinder is supplied directly by the cold mains water. Operating at mains pressure, unvented systems provide excellent flow rates, enhancing shower and bath performance.
Unvented systems also eliminate the need for a coldwater tank in the loft, freeing up valuable space and reducing the risk of freezing during winter. Since these systems don’t rely on gravity to distribute hot water, the cylinder can be installed almost anywhere in your home.
Additional benefits include reduced system noise, as there’s no cold water cistern refilling, and improved water quality, as the sealed system prevents contamination of cold water.
Direct systems
In a direct cylinder system, hot water is heated directly by an internal element, such as an immersion heater. While direct systems can be more costly to operate, they are often the only option for homes without gas access, such as mid-level flats. In these cases, homeowners can take advantage of Economy 7, which offers cheaper electricity rates at night to heat water.
Typically, these cylinders are equipped with two immersion heaters—one for peak electricity and another for off-peak use. It’s essential to set these heaters on timers correctly to ensure you’re minimising costs. Heating water with the peak immersion heater during off-peak hours can lead to unnecessary expenses.
Direct systems can be configured as either vented or unvented, providing flexibility to suit different home requirements.
Indirect systems
Most hot water cylinders are heated using an external heat source, such as a gas boiler or solar thermal system. In this setup, hot water is heated and then circulates through a copper coil within the hot water tank. This allows heat to be transferred from the external source to the water inside the tank.
Indirect cylinders typically include a direct backup, such as an immersion heater, ensuring you can still produce hot water even if the boiler is out of service. These systems can be configured as either vented or unvented, offering flexibility based on your needs.
For expert advice or to schedule an appointment with one of our engineers, please contact us.
Unvented Cylinders FAQ’s
Here is our frequently asked questions, find answers below or get in touch.
An unvented cylinder is a water storage tank that connects directly to the mains water supply, providing hot water at high pressure. Unlike vented cylinders, it doesn’t require a cold water storage tank, making it a space-saving and efficient solution.
Unvented cylinders offer consistent water pressure, even when multiple taps or showers are in use. They save space as they don’t require a loft tank and provide clean, fresh water directly from the mains supply.
Yes, unvented cylinders should be serviced annually by a qualified engineer to check the pressure relief valve, expansion vessel, and other safety components. Regular servicing ensures safe operation and prolongs the cylinder’s lifespan.
Unvented cylinders are ideal for homes with high hot water demand or multiple bathrooms. However, they require a good mains water pressure and flow rate to function effectively. A professional assessment can determine if an unvented cylinder is right for your property.
