Choosing the right hot water cylinder can make a noticeable difference to water pressure, comfort and everyday convenience. Gledhill unvented hot water cylinders connect directly to the incoming mains water supply, allowing them to deliver powerful hot water to suitable taps, showers and baths without needing a cold-water storage tank in the loft.

Gledhill offers direct, indirect, slimline, pre-plumbed, solar and heat-pump-compatible models. Consequently, there is a solution for many different homes and heating systems. This guide explains the main options and the points to consider before ordering.

Why choose a Gledhill unvented cylinder?

Gledhill is a well-established British hot water cylinder manufacturer. Its unvented ranges include models made from corrosion-resistant duplex stainless steel and options designed for different budgets, installation spaces and heat sources.

• Mains-pressure hot water: enjoy strong flow at suitable showers, baths and taps.
• No loft tank required: this can free valuable space and simplify the property’s water-storage arrangement.
• Direct and indirect choices: select a cylinder heated by electricity or by a boiler, depending on the system.
• Durable construction: selected Gledhill ranges use highly corrosion-resistant duplex stainless steel.
• Wide choice of capacities: models are available for smaller flats through to larger family homes.
• Specialist options: Gledhill also produces slimline, pre-plumbed, solar and heat-pump cylinders.
• Long-term reassurance: eligible Gledhill unvented cylinders carry a 25-year cylinder warranty, subject to registration, correct installation and the manufacturer’s terms.

Direct or indirect: which type do you need?

Choosing the wrong type can cause significant installation problems. Therefore, always ask a qualified heating engineer to confirm whether the property needs a direct, indirect, heat-pump or solar model before ordering.

Popular Gledhill unvented cylinder ranges

Gledhill Stainless ES

The Gledhill Stainless ES range is a competitively priced option available in direct and indirect configurations. Gledhill manufactures the cylinder from highly corrosion-resistant duplex stainless steel and offers a wide selection of capacities. It is a strong choice for customers who want dependable performance and recognised Gledhill manufacturing at an attractive price.

Gledhill Stainless Platinum

The Stainless Platinum range uses an internal air gap to accommodate expansion, removing the need for a separate external expansion vessel on applicable models. As a result, it can provide a neater installation and save useful cupboard space. Direct, indirect and pre-plumbed versions are available for different applications.

Gledhill StainlessLite Plus

StainlessLite Plus offers a broad choice of configurations, including standard, slimline, horizontal, solar and heat-pump options. The Slimline range is especially useful where cupboard width is restricted.

What size Gledhill cylinder should you choose?

The correct capacity depends on more than the number of bedrooms. Household size, bathrooms, showers, baths, peak-time demand and the cylinder’s recovery rate all matter. The following figures are a broad starting point only:

Important: This table is general guidance, not a system design. Bath size, shower flow rate, available reheat time and simultaneous use can change the required capacity. A qualified installer should calculate the home’s actual hot water demand.

Check the water pressure and flow rate

An unvented cylinder cannot create water pressure. Its performance depends on the incoming mains supply and correctly sized pipework. Before buying, an installer should test the property’s static pressure, dynamic pressure and flow rate. This is particularly important in homes with several bathrooms or where two outlets may run at the same time.

Can a Gledhill cylinder work with a heat pump?

Yes, but the cylinder must be designed for the application. Heat pumps generally work at lower flow temperatures than traditional boilers, so a purpose-designed cylinder uses a suitable high-output coil to transfer heat effectively. Gledhill offers dedicated heat-pump models; ask your system designer to match the cylinder to the selected heat pump and the home’s calculated demand.

Installation and maintenance

Unvented hot water cylinders include important pressure and temperature safety controls. In England and Wales, installation must comply with the applicable Building Regulations, including Approved Document G. The work should be completed and commissioned by an installer who is qualified and competent to work on unvented hot water systems.

After installation, keep the commissioning documents and register the warranty. The system should also be serviced at the intervals stated by the manufacturer. Routine checks help confirm that safety devices, controls and expansion arrangements continue to operate correctly.

Frequently asked questions

Are Gledhill unvented cylinders any good?

Gledhill offers a broad range of unvented cylinders for different budgets and applications. Selected ranges use duplex stainless steel, while specialist options cover restricted spaces, solar systems and heat pumps. The best model is the one correctly matched to the property and installed according to the manufacturer’s instructions.

Does an unvented cylinder improve shower pressure?

It can provide strong mains-pressure performance, but the result depends on the pressure and flow available from the incoming main. A site test is essential before the system is specified.

Do I need a direct or indirect Gledhill cylinder?

Choose direct when immersion heaters will be the main source of heat. Choose indirect when a boiler or compatible external appliance will heat the water through a coil. Heat pumps and solar systems normally require cylinders designed specifically for those heat sources.

How long is the Gledhill unvented cylinder warranty?

Gledhill states that its unvented cylinders carry a 25-year warranty on the cylinder and two years on components. Registration, correct installation, servicing and the manufacturer’s full warranty conditions apply, so check the terms supplied with the chosen model.

Can I install an unvented cylinder myself?

Unvented systems involve stored hot water under pressure and specialist safety controls. Installation should be carried out by a suitably qualified, competent installer who can commission and notify the work where required.