Product at a glance
425 series mechanical programmers are the simplest way to control hot water and central heating in the home. The 425 Diadem is a twin circuit, hot water and central heating programmer, with indicator lights and 16 programmes available for fully pumped systems, including independent programming of heating and hot water, and 10 programmes for gravity hot water / pumped heating systems. The Diadem is ideal for gravity systems and fully pumped systems with zone valves.
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The above units use the same backplate as H3747 and only require simple wiring changes
|* C1727 backplate change and rewire required (economical option)