Buffer Tanks
Looking for reliable buffer tanks and air separators to ensure your air source heat pump system runs at peak performance? At BES, we understand that a stable hydraulic environment is the foundation of any high-performance ASHP setup, and we are proud to stock a wide choice of high-quality vessels and separation hardware from industry-leading brands.
By keeping our prices competitive and offering fast, next-working-day delivery, we help you keep your projects on schedule and under budget. Browse our current stock of buffer tanks and air separators below to find the right capacity for your installation, or get in touch with our team if you need help sizing the correct vessel for your specific heat pump output.
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A Wide Choice of Buffer Tanks & Separators
We stock high-quality vessels and separation hardware to suit a variety of installation requirements.
Buffer Tanks
We offer a versatile range of Zilmet Buffer Tanks, including floor-standing models such as the Zilmet 50-Litre, 80-Litre and 100-Litre tanks, plus the space-saving Zilmet 25-Litre Buffer Tank with a wall-mounting bracket, ideal for compact plant rooms.
Our selection also includes Albion Aerocyl Heat Pump Buffer Tanks, designed specifically for heat pump systems. These tanks deliver premium performance in capacities ranging from 60 to 210 litres.
Air & Dirt Separators
Our SpiroCross AX-J Air & Magnetic Dirt Separators (available in 1", 1.1/4", and 1.1/2" BSP sizes) offer a dual-action solution that removes micro-bubbles and captures magnetic sludge in a single, compact unit, protecting sensitive heat pump components.
Why Are Buffer Tanks & Air Separators Needed
Buffer tanks and air separators are essential for keeping heat pump systems running smoothly. A buffer tank acts like a thermal battery, providing extra water volume to prevent the heat pump from "short-cycling", the process of turning on and off too frequently, which helps the compressor last longer. It also acts as a bypass, ensuring the heat pump has sufficient water flow even when radiators or thermostats are turned down.
To keep everything clean, our air and dirt separators protect the system by removing trapped air bubbles and magnetic sludge. By capturing these before they cause damage, the units keep the system clean and ensure it remains energy-efficient.
Choosing The Right Buffer Tank
Selecting the correct buffer tank is critical for the system’s health. While specific requirements should always be checked against the heat pump manufacturer’s technical manual, a common rule of thumb for ASHP systems is to allow for approximately 10–20 litres of buffer volume per kilowatt (kW) of heat pump output. If you are uncertain about the specific volume required for your project, always verify the manufacturer's minimum system volume requirements first.
Why Choose BES for Renewable Heating Parts?
When you are managing a renewable heating installation, you need a partner who understands the technical requirements of the trade. BES provides not only the hardware but the reliability you need to keep projects on schedule. We maintain deep stock levels of essential renewable components, from System Fluid and Pipe Insulation to Control Packs and Installation Equipment. With our excellent rating on Reviews.co.uk and our commitment to getting the right products to the right place on time, you can shop with confidence.
Frequently Asked Questions
How do I choose the correct capacity for my system?
Capacity is determined by the output of your heat pump and the total volume of your heating system. A general rule of thumb is to aim for 10–20 litres of buffer volume per kilowatt (kW) of heat pump output, but you should always refer to the specific installation manual for your heat pump brand to confirm their minimum requirements.
Do I need a buffer tank for my air source heat pump?
In many cases, yes. A buffer tank ensures the heat pump can maintain a minimum flow rate and operate in longer, more efficient cycles. It is particularly important in systems with zoning or thermostatic radiator valves (TRVs) that can restrict flow.
Are BES’ buffer tanks compatible with all brands of air source heat pumps?
Most of our buffer tanks are designed as universal hydraulic components. As long as the capacity and connection sizes are correct for your system's flow rate and kW output, they can be integrated into most ASHP setups.
What are the material considerations for these tanks?
Our steel buffer tanks are built for robustness in closed-loop heating systems. When installing in a closed-loop environment, always ensure the system is treated with the correct corrosion inhibitor to protect the tank's integrity and ensure long-term performance.
Can I get next-working-day delivery on these tanks?
Yes, our buffer tanks and separators are eligible for next-working-day delivery across most of the UK, provided your order is placed before the daily cut-off time.