Aquinox Heat Pump Buffer Vessel

Heat Pump Buffer Vessels

The Aquinox Heat Pump Buffer Vessel is utilised to add volume to your existing heating system; heat pumps require a minimum system volume to function efficiently. Adding a Heat Pump Buffer Vessel ensures a consistent flow rate and system volume are maintained. A heat pump will keep emitting heat even with no demand, and an Aquinox Buffer Vessel will facilitate the storage of this excess heat for later use. 

We manufacture our buffers from Duplex Stainless Steel for its corrosion resistance.

As the buffer vessel will contain warm water, it will prevent the heat pump from going into defrost mode during cold temperatures as warm water will remain cycling.

If you’re not sure whether your heating system requires a buffer tank (as not all do), or what size vessel would be necessary, we would suggest consulting your heat pump installer and/or supplier for advice.

Having a Buffer Vessel reduces the risk of short cycling, leading to inefficiencies and even damage to the heat pump system, leading to a longer lifespan for the system and the heat pump unit itself.

Our buffer vessels range from 15 Litres to 100 Litres covering most requirements for the heat pump market.

If you require a larger buffer vessel – you can view our range here or get in touch.

Our service doesn’t include recommending the correct product designs for our customers’ jobs, so the effectiveness of their use within a system should, therefore, be determined by a competent installer.

Stainless Buffer – 3/4 View
Stainless Buffer – Cased
Stainless Buffer – Armaflex Finish

Example Specification

  • Working Pressure – 4.0 BAR
  • Test Pressure- 6.0 BAR
  • Operating Temperature – -5°C to 95°C
  • 4 x 1″ Female Connections
  • 1/2″ Auto Air Valve
  • 1/2″ Thermostat Pocket Connection
  • Includes Wall or Floor Mounting Brackets
  • 5 Years Warranty
SizeArmaflexSteel CaseVolume
300x184mm320x205mm320x210mm8 Litre
450x184mm470x205mm470x210mm12 Litre
480x200mm500x220mm510x260mm15 Litre
800x200mm820x220mm830x260mm25 Litre
820x250mm840x270mm845x295mm40 Litre
975x250mm995x270mm1000x295mm48 Litre
760x375mmN/A820x450mm80 Litre
950x375mmN/A1010x450mm100 Litre

Get In Touch

Our range of Heat Pump Buffers is made to order so can be manufactured to your unique requirements. If you are interested please get in touch below;


    Company Name (If Applicable)


    What volume do you require the unit to hold?
    What Connections do you require?
    Connection Size Quantity
    22mm Compression
    28mm Compression
    1" Female
    3/4" Female
    1/2" Female
    What Finish do you want on the buffer(s)?
    What Quantity would you be looking to order?

    17 SUBMIT

    After submitting this form, we'll provide a quotation based off the information provided and aim to respond within 48 hours.

    Frequently Asked Questions

    What is a buffer vessel?

    A buffer vessel is a key part of a heating system, storing heat from various sources like solar or solid fuel. It prevents system cycling, adds stability, and allows for controlled distribution of heat, even to systems that can’t usually handle certain sources. In short, it optimizes heating efficiency by storing, stabilizing, and controlling heat distribution.

    Learn more about the purpose of a buffer vessel here.

    What size buffer tank do I need?

    It is strongly advised that you reach out to a knowledgeable heating engineer who can determine the size of the buffer tank you need.

    Can't find what you're looking for? We're here to help.

    If you can't find what you're looking for please let us know your email and query and we'll be happy to help. 

    If you would like us to give you a call back, please provide your contact telephone and we will be in touch.

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