Cylinders and thermal stores which are ideal for an eco-friendly home with a need for a reliable, energy efficient hot water supply

Why choose a Grant cylinder or store?

Wave cylinders and thermal stores have been developed to the highest specification, as you would expect from any Grant product. The cylinders have powerful mains-pressure performance with exceptionally high hot water flow rates, while the thermal stores have been specifically designed to enable complementary technologies to be easily combined.

The Wave range of cylinders and stores have sizes ranging between 125 and 500 litres, and are designed to be coupled with almost any household hot water system from oil and gas boilers to electric heating, air source heat pumps and even solar thermal.

Grant Wave Cylinder RangeGrant Heat Pump Cylinders– Unvented indirect main pressure models for either Grant Aerona Air Source Heat Pumps or combining ASHP with solar thermal systems. Sizes range from 125-400 litres.

Grant DuoWave Cylinders – Unvented hot water cylinders direct with solar single coil and indirect solar twin-coil models for renewable applications. Sizes range from 170-500 litres.

Grant DuoWave Plus Cylinders – Open-vented or unvented hot water cylinders indirect triple-coil mains pressure models for combining solid fuel, biomass, gas, electric or oil-fired boilers and solar thermal systems. Available in a 300 litre version only.

Grant ThermaWave Stores – Open vented and sealed system thermal stores for combining multiple heat sources in a variety of configurations. Available in 250, 300, 400 and 500 litre versions.

• 25 year material guarantee on cylinder/store shell (Subject to Terms & Conditions)
• 22mm and 28mm compression fittings
• No anode required
• Immersion heater
• Fast recovery stainless steel corrugated coils (all indirect and solar direct models)
• Labelled and colour-coded tappings
• Global warming potential (GWP) = less than 3
• Ozone depletion potential (ODP) = 0

Hot water cylinder production and control

The cylinders are produced using high quality 1mm thick duplex 2034 stainless steel. Models which incorporate internal coils are constructed from 20mm or 25mm corrugated stainless steel tube, giving maximum heat transfer, high efficiency and quick recovery. Grant Wave hot water cylinders and thermal stores are pressure tested to a full 12 bar.


All Grant cylinders are manufactured in accordance with BS EN 12897m the specification for unvented hot water storage vessels. They all comply with Building Regulations G3 and Water Regulations. Hot water cylinder performance complies with the requirements BSEN806, BS1566 and BS7206 and meets the NHBC criteria.


All cylinders are fully integrated within the Code of Practice for the installation and commissioning of central heating systems – Benchmark. The aim of the scheme is to advance professionalism of the heating industry and increase levels of customer satisfaction.


Grant cylinders and stores have a full two year component guarantee as well as a twenty-five year guarantee on the stainless steel cylinder shell from the date of installation, unless the installation is more than six months from the date of purchase in which case the guarantee period will commence six months from the date of purchase. All guarantees are subject to the product being installed in accordance with the manufacturer’s instructions and serviced on an annual basis. On completion of the installation, the system should be commissioned by a competent person and the cylinder registered online with Grant Engineering (UK) Ltd.

Cylinder and Thermal Store Case Studies

Living with a Grant Vecta biomass boiler

Grant UK visited Mike and Sarah Hodgson who recently had a Vecta wood pellet boiler installed at their property, to discuss why they chose this renewable technology and to uncover a homeowner’s perspective of living with biomass. At the beginning of 2017, Mike and Sarah Hodgson had an internal VectaRead More

Townsends take up renewables

Established in 1945, W.J Townsend & Son is a family run business providing domestic customers in Towcester and surrounding areas with a comprehensive range of plumbing and heating services. The business has been in the family for over 75 years with William John Townsend, founding the company. Andy his sonRead More

East Green Energy lead the way with Grant Spira

Renewable energy specialists East Green Energy are leading the way by installing an award wining Grant Spira Wood Pellet Boiler in their showroom at the Company’s Suffolk headquarters. Believed to be the only showroom in East Anglia with a fully working Wood Pellet Boiler, it is certainly generating a greatRead More

Installer promotes advantages of renewable heating

Long established plumbing and heating installers, Great Yarmouth Heating Company Ltd, is promoting the benefits of energy saving, by kitting out their premises with an array of Grant MCS approved renewable technologies. Based on Gapton Hall Industrial Estate, GYH was founded in 1971 and has installed, serviced, and maintained GrantRead More