Central heating system thermostat

Thermostat by Teddington. About 1930. Bakelite (TM); brass; Art deco styled Bakelite angular casing with circular knurled knob.

Part of the Bob Gray collection of electrical objects.

This thermostat was used to help maintain a constant temperature within a room as part of a central heating system. The thermostat senses the temperature within the room and switches the heating on or off depending on whether the system is too cold or too hot. Thermostats were expensive devices and were rarely fitted despite their energy saving benefits. This is an early mass production model with art deco styling. Thermostats were so unusual at this time that one was displayed in the Palace of Engineering at the British Empire Exhibition at Wembley placed between a heater and a cooling fan so that people could see it working.