How does a Controller work?
A Temperature Difference Controller is an electronic circuit with two or more temperature probes. It compares the temperature of the water in your panel with that in your hot water tank, to assess whether it is beneficial to start pumping. Typically it’ll look for a 6°C differential before switching the pump on and it will continue to make this assessment every 15 seconds, switching off before any cooling occurs. The controller shown here is a 12 volt unit, operated by a microchip which can be programmed to suit the customer’s individual needs, with features such as Frost control, which is particularly useful for customers connecting evacuated tube panels in the direct (SolarTwin style) method.
