Siemens RDH100 Digital Thermostat

Wanted a digital thermostat to replace old Honeywell mechanical device. This SIEMENS one is solid, well made, clear and easy to install and use. Only slight niggle is that it is large but .. so what.. its good.

Installation is simplicity itself, and I was fascinated to see it had not only binary control (on/off) but also PID (Proportional Integral Derivative), something I certainly didn't expect. Frankly on my system the binary control is perfectly adequate, Good clear display and even my wife likes the comparative hi tech display that our previous and very ancient Honeywell mechanical stat simply did not have. Easy to see when the heating is actually on/off, what the setpoint temperature is and what the actual measured temp is. All in all, a very nice, simple bit of kit.

Nothing wrong with the thermostat but you simply cannot pair with an existing receiver. Siemens usually supply thermostat and receiver together and pre-sync at manufacture. Buyer beware. These thermostats should not be sold separately.

Very well made and simple to fit. Replaced it for my old Honeywell mechanical stat in 15mins

Easy to installLooks greatWorks very well

This replaced a cheaper version with a timer. The temperature appears accurate and the large display is easy to read.

Easy to fit and use, big improvement over the old dial one it replaced

No fitting instructions. Once installed, it switched the heating on, then off immediately. Unfortunately, left it too long before installing it, now outside return period, so it goes in the bin. Re-installed very old Honeywell analogue switch, works fine!