500 Litre buffer tank or vessel

500 Litre buffer tank or vessel with energy class c insulation levels hot water storage for hydronic heating systems


Our 500 Litre buffer tank or 500 litre buffer vessel, is a hot water buffer tank normally used to store heating hot water or increase the heating system’s hot water volume. This energy is retained for later use and results in fewer but longer heating cycles for the heating system with our buffer tanks or accumulator tanks.

500l buffer tank for a heating system

This 500L buffer tank can be used on various heating systems, but is often used in conjunction with renewable heating systems such as biomass boilers or low carbon systems such as ground source heat pumps or air source heat pumps.

Air source heat pumps

For a heat pump to operate at peak efficiency, our buffer tank, also known as a buffer vessel, ensures minimal compressor run times and minimum water flow rates. For air source heat pumps, a buffer is necessary because it supplies the defrosting energy for the heat pump. If a heat pump is the only source of heating, it is also possible to integrate an electric immersion element to provide additional heating as needed to our multi port buffer tanks.

Specification of our buffer tank or vessel

Specification of our 500 Litre buffer vessel or 500l buffer tank

500 Litre buffer tank or vessel dimension details Flexiheat UK

Out 500L buffer vessel or tank – overall height 1,770 mm, overall diameter 850 mm with insulation – 650 mm diameter with insulation removed.

Tank storage capacity – 500 Litres

Height – 1,770 mm

Diameter with Insulation: 850 mm

Diameter without Insulations: 650 mm

Product insulation is polyurethane – 50 mm insulation

The insulation is removable – which allows you to get the buffer tank through a standard doorway access

Our 500l buffer tank is a great quality product at a great price

Buffer tank weight – 108 Kg when empty – 508 kg when full with hot water

8 x connection tapping’s – 40 mm (1 1/2″ ) female bsp – designated “KP” on the above drawing

4 x Thermometer or sensor pockets – 15 mm (1/2″) female bsp – designated “T” on the above drawing (sensor pockets are 1/2″ female threaded)

1 x Air vent eliminator or safety valve tapping or bsp safety connection – 40 mm (1 1/2″) female bsp- designated “OZ” on the above drawing

Full port dimensions off the floor for our FH16.500NB-O which is the 500 Litre model product is listed in the following data chart

500L buffer vessel dimensions all in mm Flexiheat UK

All dimensions are in mm for our buffer tanks

Buffer tank maximum working temperature – 95 Degrees Celsius

Buffer tank maximum working pressure – 3 Bar

With plenty of tapping’s this 500L buffer tank can be fitted with additional immersion heaters as a backup or top-up heat source.

This 500L buffer tank is manufactured from mild steel, so corrosion inhibitors must be used with this product.

Download the Flexiheat UK 400 to 600 Litre heating buffer tanks vessels brochure

Should you require another capacity or volume buffer tanks or a higher working pressure, then we do a full range of buffer tanks which are listed on their dedicated webpage.

Applications – hydronic heating systems

Our 500l buffer tank can be used with heat pumps, log fired boilers, gasification boilers, wood pellet boilers, or even traditional gas or oil boilers, Flexiheat UK offers a variety of multi-port buffer tanks and accumulator tanks.

Sizing criteria for a 500l buffer tank

Here are some guidelines on sizing for our 500L buffer tank

Air source heat pumps or ground source heat pumps: approximately 25 litres per kW of heat pump output (recommended by BS EN 14511 for defrosting of the heating system).

Wood pellet boilers: a minimum of 10 litres of tank volume for every 1 kW of boiler output.

Solid fuel boilers: a minimum of 30 litres of tank volume for every 1 kW of boiler output.

Wood chip boilers: a minimum of 12 litres of tank volume for every 1 kW of boiler output

Gasification boilers / log fired boilers: a minimum of 50 litres of tank volume for every 1 kW of boiler output.

Thermal storage tank or vessel 500 Litres capacity

If you require more product information, availability, technical support , check stock levels, delivery times or get prices on our 500 Litre buffer tank or vessel for heating hot water, then please don’t hesitate to get in touch. Contact our sales service team on 01202 822221 or use our email contact form via the contact tab above to message us. Connect with us on Facebook or Twitter for our latest products updates and special product price deals.