Thermal Breaks

A thermal break as shown above is a device used to separate the heat generation and heat emission sides of the water circuit.

A heat pump is different to a boiler. It requires significantly greater water flow to operate correctly than the equivalent boiler system and at lower temperatures.that may actually harm a combustion based system. It is very sensitive to low water flow and a thermal break will protect the heat pump from nuisance trips or damage resulting from low demand and reduced flow rates.

More importantly it neatly delineates between the responsibility of the heat pump engineer and the plumber. It is the heat pump engineers responsibility to get hot water to the thermal break and the plumbers responsibility to distribute that heat.

We very strongly recommend the use of a thermal break with all heat pump systems, including simple ones such as the one shown above. They become a necessity when using a more complicated system with two, three or more heat sources and two or more heating circuits.

In fact using a thermal break makes a complicated system such as, for example, a three heat pump with boiler backup heat generation circuit connected to two radiator circuits and an under floor heating circuit easy.

A thermal break can be either a low loss header or a buffer tank.

Low Loss Headers

A low loss header is suitable for most heat pump applications and is much smaller and quicker to respond to demand than a buffer tank.

It consists of a small water reservoir, typically of one or two litres, with a boiler flow and return connection on one side and a heating flow and return connection on the other. At the top is an automatic air vent and at the bottom is a drain point.

We have a fantastic range of low loss headers suitable for a wide range of capacities. They are pre insulated and have pockets for temperature sensors or thermostats as standard. We can also supply manifolds for two, three or more heating circuits. We can also supply pump sets for connection to these manifolds. They are all high quality and very reasonably priced.

Low Loss Header with manifold and pump sets.

The pump sets shown are, from left to right, Universal model with flow and return thermostats, Under Floor Heating model which has a mixing valve and Radiator or Fan coil model with three way and differential pressure valves.


Low Loss Header and Low Loss Header with Manifold

We keep these headers on the shelf for overnight delivery while the pump sets and manifolds may take a few days to deliver. These have become one of our most popular products.

Buffer tanks

These are similar to a low loss header but are much larger and act as a water storage device as well. Typically you might use a tank rather than a header where the water circuit is below the 50 litre minimum for an Aquarea system.

They can also give a reservoir of hot water for heating to enable the radiators to stay warm when the heat pump is generating domestic hot water. Typically a 200 litre buffer tank will give around eight minutes of water with a 9KW heat pump.

If total water quantity exceeds 200 litres then you will need an additional expansion vessel.