Pictured below is the latest (November 2014) version of our Differential Thermostat designed to be used in simple solar water heating systems, fan controllers moving warm air to cooler areas, and many other applications.

This device is based around this solar water heating pump controller design which we have been selling now for over 8 years. When the left hand side temperature sensor is measured to be hotter than the right hand side sensor, the up to 2 Amps output is turned on, and remains on until the temperature difference between the two sensors has fallen to zero.

This output can be used to directly power small pumps or fans etc, or can be used to switch a relay which can in turn switch high current or higher voltage devices.

Click here for more details and/or to purchase this new Differential Thermostat from the REUK Shop.