Drayton 123070 LP522 (Mk4) 2 Channel Programmer, White

Product Information

Allowing different programmes for weekdays and weekends and independent timing of each channel. LP522 provides the ability to control central heating even more efficiently. No longer do systems have to switch on as early at weekends as they do on weekdays. The Nest thermostat is connected to the Heat link terminals T1 & T2 (or it can be powered using a separate plug in power supply) If you are using T1 & T2 for the thermostat, the earth terminal just to their left, also needs connecting to earth. The HW didn't work on the Nest, which was a surprise. So I just took a wire off, and it now works fine. It was great to have hot water in the morning without getting out of bed and pressing a button. However, my CH wasn't working on the scheduler, or the dial.

And all central heating should come from the same 230 volt supply, otherwise and UPS system to keep it running will not work. However my TRV's with this house (oil fired) have not worked anywhere near as good as with late mothers house (modulating gas) how much down to how pipework installed and how much down to on/off boiler I don't know. Finally the old thermostat needs to be decommissioned. The simplest way is to leave it in place and put both wires in the same terminal so that they are electrically connected. I decided to get a Nest 3rd Gen (Learning Thermostat) after reading the forums on here. I'm in a rental property with no thermostat and I want to save money on heating, and I figured I could probably take this with me if I move (I also like tech). boiler turned off in case heating was left on as I can’t see if it is on the display (but could hear it working)

I assume you are asking this for simplicity of installation, it's a bit of a fudge to leave the LP522 in place, but you could. The simplest way would be to leave the heating set to be permanently 'on' at the LP522 and replace the old mechanical thermostat with a WiFi controlled 'wired' smart thermostat.

With the majority of installations, the thermostat is connected to the wiring centre, but not always. The programmer is usually the second most common place, generally because it is downstairs and closer to the thermostat than the wiring centre which can be upstairs in an airing cupboard.Another thing is that the hot water was a lot hotter than it usually was but perhaps this was because the water was left on for longer than it usually does.