The THERMflow thermal store has been the cornerstone of our thermal store ranges offered for over thirty years, providing homeowners and installers alike to maximise the available heat sources within a property to provide both heating and mains pressure hot water. As a result, McDonald Water Storage are recognised within the industry as the thermal store experts, with the ability to provide the perfect solution for the installation requirements.
Our THERMflow works at the heart of your heating and hot water system to supply the central heating system in addition to mains pressure hot water. With our unique design and manufacturing solution, we can offer significant cost savings both during installation and ongoing running costs.
Through continuous research and development, we have made a number of changes to the product range to add to the benefits already offered by THERMflow. All models are now supplied with 50mm high density foam insulation and white cased finish as standard!

This change provides fantastic heat retention and a lower heat loss than the original spray foam solution, ensuring all the energy put into the thermal store is retained for as long as possible. In addition, we are also offering insulation upgrades to customer specification, with 75mm and 100mm options available alongside optional external pipework packs to ensure efficiencies whilst saving installation time.
Extensive work has been carried out to ensure the tapping positions on the standard range ensure maximum input and performance from the relevant heat source, alongside the integration of the premium grade copper coils ensuring the highest possible heat transfer, ultimately reducing the running costs.
However, there will always be instances where there are unique installation requirements that do not suit a standard product … not a problem. The THERMflow is the most customisable thermal store on the market and as a result, every model in the range can be supplied with custom connections, positioned exactly where you need them to minimise additional pipework and installation costs. We can bespoke design the cylinder itself to fit into the tightest spaces, even as rectangular units with our CUBEflow range.
In these times of high energy bills, it is essential to maximise all the available energy sources, especially renewable technologies, to reduce your running costs.
THERMflow offers the perfect solution, with the ability to maximise all energy sources for both heating and hot water for the home with a wide range of models to incorporate heat sources such as solid fuel, solar thermal or low carbon generated electricity.
With a comprehensive range of both combination and standard cylinders, click here to see which model will suit your next project.
Wayne Hyde
Marketing and Project Manager
Having been in the cylinder industry for nearly 20 years, in both product and marketing roles, I have extensive knowledge of all aspects of hot water storage, from domestic through to commercial applications, including vented, unvented and thermal store solutions.


