heat pump tanks

Buffer tanks are central components of modern heating systems. They connect heat suppliers such as heat pumps and heat consumers, fresh water stations and heating circuits. Thanks to the storage volume, heat generation and heat demand are independent.

When choosing the buffer tank for heat pumps you have to consider different aspects:


  • usage behavior
  • existing space
  • hot water demand
  • investment costs
  • running costs
  • locking periods / performance of the heat pump


unitec Energietechnik GmbH covers the entire range of possible answers. In addition to the standard solutions presented here, individual solutions can also be worked out!

One-tank system

The heat pump is responsible for both - room heating and drinking water heating. Systems with one tank allow both requirements in one container, these differ in the type of domestic water heating. In external systems, the process water is heated - using a plate heat exchanger, which is installed outside of the hot water tank. Internal systems, so-called combination tanks, work either with an integral boiler - that means with a stainless steel tank in the buffer tank - or a stainless steel corrugated tube heat exchanger built into the buffer tank. If additional heat generators are present (such as a woodburning stove), they can easily be integrated into the system.

Electronically controlled fresh water modules achieve a high tapping performance and at the same time lower temperature differences. This works with the help of the very large heat exchanger surface. The external stations have variable speed high efficiency pumps with low power consumption and are easy to maintain. The buffer tanks of unitec Energietechnik GmbH combine optimal flow behavior, volume utilization and space on site. The PFS series can also be used to implement system separation when using solar thermal systems.

The integral boiler made of stainless steel can easily handle short-term high flow rates and thus plays its strengths in installations with low base load and few power peaks. In order to ensure the stratification of the buffer water in the tank, hydraulic layer switches are installed at the supply and return connections.

Our WP combination tanks are tested for stratification efficiency by the SPF in Rapperswill.


Stainless steel

Stainless steel tanks meet the highest hygienic standards. The homogenous surface of stainless steel is and remains hygienic even after many years of usage. The EWS series is the economic answer to the question of the optimal hot water tank for drinking water. Bacteria and other organisms do not find fertile ground on the vitreous enamel.


The hot water tank for the highest demands:
Long-lasting quality through high-quality stainless steel, processed using the latest technology and sustainable surface treatment through acid pickling bath and passivation. Since heat pump flow temperatures are lower than for other heat generators, the WPX stainless steel heat exchangers contain heat exchangers that are significantly larger in area than compared to normal hot water tanks.

The EWS series is the cost-effective alternative to the WPX series and offers the right tank for every loading situation. With corresponding heat exchangers and in various sizes, the enamelled hot water tanks EWS integrate optimally into almost any domestic water system. Thanks to the high-quality enamelling according to DIN 4753, in combination with an anode, the containers combine longevity and hygiene.


Two-in-one tank


The EWS 1 300 + 100 WP represents a space-saving solution. The tank, which was specially developed for heat pumps in single or multiple dwelling, combines the classic enamelled hot water tank and a small buffer tank in one unit. In order to ensure an optimal clock-low operation, it is always advisable to integrate a - at least small - buffer tank into the system.


Our water tanks are up to any requirement. Whatever your purpose for your project is - we will find the right solution.

Thanks to our many years of know-how, we can individually plan and deliver water tanks for every need in the shortest possible time.
The individual components are designed so that they can be put together according to individual requirements.

Business and industry require very different solutions than a single or multiple dwelling. We configure the perfect fit solution for every initial
situation - with perfectly coordinated components and well thought-out design in terms of efficiency and minimum raw material consumption.