Skip to main content


Combisave is a device that fits onto a combination boiler and saves water and gas during the heating of domestic hot water.

After conducting a series of field tests the company approached the Energy House team to carry out a flow test on the unit under controlled internal and external conditions.


  • Study flow rates and temperature of the hot water outlet in the kitchen  
  • Test a prototype device  
  • Film an instructional video of how to install the unit.  

What we did

  • The environmental chamber was held at 5°C  
  • The Viessmann combination boiler in the Energy House was fitted with a Combisave device  
  • The house temperatures were set to 21°C in the main living area and 18°C in other areas  
  • Flow and temperature was recorded from the hot water outlets.  


Combisave used the data to ratify the design of the unit and successfully launch it onto the market, achieving sales of 30,000 units in the first year of trading.

“Developing a new innovation, bringing it to market and bringing it to people’s attention is very difficult but it would have been a whole lot harder without the support of the Energy Hub team at the University of Salford.”

Combisave 2014

Combisave imageCombisave logoEDF logo