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Solar Products
TD Switch
Description: This is not a controller as such, it's more a simple temperature differential switch. But it has many uses as well as being the most basic form of turning the solar circulating pump on and off. Installers use it to allow the transfer of heat from pre-heat cylinders to the main store, or add the switch to allow a heat dump function.
The TD switch is a basic differential temperature controller. It operates by comparing the difference in temperatures between a black sensor (collector sensor) and a grey sensor (cylinder sensor) to control a solar circulation pump in a solar thermal system. It also has an anti-freezing function.