Baxi combi boiler and uSense wired thermostat - installation help


I have a Baxi 800 combi boiler, with a uSense gateway and wired thermostat which I want to replace with a wired Tado thermostat.

I've been going through the instructions sent to me after the support request and a couple of things haven't been entirely as in the instructions and I don't seem to be making any progress with the support emails so hope someone here can help.

First issue was that the diagram of the gateway in the instructions first says to 'Loosen the screws of the cable connections and remove cables from the screw terminals labeled with OT and R-Bus' and then as the next step to 'Connect the cables from the terminals ON/OFF to one side of the luster terminal. Connect the cable from the terminals R-Bus to the opposite side of the luster terminal.' - my Gateway only had cables going into the R-Bus and the ON/OFF terminals. So I followed that up with support and they said to ignore the bit about OT and remove and connect the R-Bus and ON/OFF to the luster as in the diagram in the instructions. Which is fine though I have to say the subsequent confusion has now made me a bit wary of the whole process!

The instruction leaflet says I need 'an additional 2 way connector you can get in any DIY store.' and provides this picture:

But gives no more information about the size of connector/luster I should get. I've asked support, and all I've got in response is 'The connectors 5A or 15A are not necessary, you only need a 2-way connector.' and subsequently a photo of a different style of luster terminal but again with no information about size. I've queried again but it's all gone quiet. I've been trying to get this thing sorted since Monday and it really doesn't feel like it should be this complex a task!

Can anyone here help?

Thanks in advance!


Best Answers

  • GrilledCheese2
    GrilledCheese2 ✭✭✭
    Answer ✓

    A 5 Amp connector block will be more than adequate. A typical domestic boiler installation will be fused at 3 Amp, plus Tado devices are rated at a maximum of 3 Amp. You could safely use a 15 Amp connector block, however the dimensions will be bigger.

  • katestew
    Answer ✓
    That’s perfect, thank you so much!