[deepsy]

The relay is controlling the main voltage input and it's similar to http://i.ebayimg.com/00/s/NTAwWDUwMA==/z/ZS0AAOSwr81UNgc9/$_.... The relay's function is to act like a central switch. I have also a servo attached to the thermostat and it's only role is to spin the thermostat controller. The servo is similar to http://www.conrad.com/medias/global/ce/2000_2999/2000/2060/2...

[anfractuosity]

You could also look at SSRs, which tend to be easily controllable with logic level outputs on a microcontroller.

[Freak_NL]

Solid State Relays (SSR) do work great. Internally they use an LED to close the switch rather than the mechanical coil mechanism used in the classic click relays; these are totally silent.

I am using one to turn on/off the mains power of a 12VDC transformer. The nice thing about an SSR with an input range of 3–30V (a common type) is that you can drive it directly (and safely!) from a Raspberry Pi GPIO pin (3.3V).

[deepsy]

Thanks! Will definitely look into them :)

[cdowns]

Thanks!