Understanding the Basics of Header Tanks

Header tanks, also called feed and expansion tanks, are used in all vented hot water and central heating systems, as a means of supplying a particular appliance or system with cold water, as well as taking up any expansion that comes as a result of the water being heated up.

A copper or stainless header tank has the same purpose as a plastic header tank, except that it provides extra protection where water can get exceptionally hot in solid fuel installations. Unlike many plastic header tanks, our header tanks come with all water connections pre-installed.

The main benefit of using a copper or stainless header tank to feed your hot water cylinder or heating system is that, unlike the more common plastic tanks, they will not be susceptible to melting or warping due to prolonged overheated water. This can be a particular problem on a system which incorporates a solid fuel boiler or uncontrolled heat source, as they are capable of heating the water to in excess of 100°C.

Header Tank Features

Our feed and expansion tanks have the following features as standard, which saves installation time and provides overheating protection all around.

  • Manufactured in copper or stainless to prevent tank melting and deformation
  • Pre-installed float valve with copper float
  • Pre-installed cold feed connection in 22mm compression
  • Pre-installed overflow connection in 22mm compression ready to add copper overflow pipe
  • Insulation fitted to tank
  • When used with a thermal store, the float arm is pre-adjusted

We supply the header tanks pre-insulated with spray foam insulation on round units and insulation board on the rectangular units, both to a depth between 25mm and 30mm. This will help to contain any heat that is returned to the header tank by expansion, increasing efficiency, but also eliminating the risk of frost damage.

Learn more about Header (and Feed & Expansion) tanks here.


Height (mm)Diameter (mm)Literage (Volume)Max System Size (Litre)


Height (m)Diameter (mm)Literage (Volume)Max System Size (Litre)

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