Water Source Heat Pumps (WSHPs)

Water-to-water heat pumps providing heating and cooling services to new build and refurbishment projects through an open or closed loop system.

Water-to-water heat pumps providing heating and cooling services to new build and refurbishment projects through an open or closed loop system.

Water source heat pumps (WSHPs) can operate as open or closed loop systems. An open loop system requires a large body of water such as a river, lake or canal, to directly cycle source water through a heat pump unit to extract heat. Closed loop systems, on the other hand, have a sealed water loop linking to a separate plant, with dual heat pumps meaning they can benefit from being low temperature (or ambient) networks.

The Zeroth Energy System

The Zeroth Energy System is a proven solution that utilises a central ambient loop to supply energy to in-apartment heat pumps. These uplift the energy from the central loop to provide space heating, domestic hot water, and cooling to residential apartments.



Efficiency and Cost

We offer heat pumps which balance efficiency and cost to offer units designed to benefit you during the compliance process and create efficient and low carbon building. Heat pump efficiency is measured as a Coefficient of Performance (COP).


Energy compliance

Dual heat pump systems can benefit projects in areas requiring carbon targets beyond Part L, such as London. Although our solution can be used with your choice of plant, pairing it with an ASHP offers high efficiencies and provides commercial benefits to designers.

Application Design

Our specialist engineers are available to offer you guidance and advice on choosing a heat pump system for your project which is designed around your specification, building requirements, space limitations and budget. We can also offer advice on buffer vessels and cylinders, as well as hydraulic schematics.

Product specification

Our Zeroth Energy System is our range of closed loop WSHPs, designed to work as a low temperature (or ambient) network for apartment developments:


Product Range Description Nominal Rating at S25/W35* Controller Max Flow Temp
Zeroth Energy System A water-to-water in-apartment heat pump connecting to a low temperature network to provide heating, hot water and cooling services to residential apartments 4 & 6.4kW In-built user-friendly controls, with option for external inputs to third party controllers 55°C heating
*S25= Source temperature at 25°C / W35= water temperature 35°C

If you are looking for an open loop WSHP, we are currently reviewing our existing European range into the UK market. We believe in working with industry to bring a product to market to make sure it meets all necessary requirements. Are you interested in applying this type of system to your project? Contact us to be a part of the discussions.

We offer a wide range of CPD UK and CIBSE accredited CPDs covering different aspects of the design and specification of heat pumps. All CPDs can be delivered online or in person.


Dimplex is here to assist you in your project with expert information. Our frequently updated and curated content library is here to break down key information, finding you the correct specifications and saving you essential time for your project.

Specifier Hub

We can offer hands-on face-to-face training on Dimplex products, including heat pump principles and servicing, and a course covering our Edel hot water heat pump.

Product training

We offer bespoke heat design solutions for your home or project and design support and guidance when specifying HVAC solutions

heat design team