Replacement Wireless Thermostat Wiring

[John Williamson]

I am replacing my old RF thermostat (Tower RF-205) with a Heatmiser RF-Switch but just wanted confirmation on the wiring. The old thermostat has 4 terminals. Live and Neutral I'm happy with but for some reason they have labelled the other two Out 1 and Out 2.



The new receiver has a ton of terminals but assuming I am replicating only existing wiring to control the central heating I assume I connect L,E,N from Mains, COM1 in the below diagram to L and NO1 to what is currently connected to 1 in the above diagram (Out 2).



Can anyone please confirm. Photo of existing (working) wiring below:



Many thanks in advance. Boiler is a Vaillant ecoTec 832 in case that's helpful.

 

[stem]

Terminals 1 & 2 are simply a switch. When the Tower is 'on' they are electrically connected together. The diagram shows a permanent live is connected to 'L in' and the switched live comes from 'L out'

3 & 4 (N & L) are for the 230V supply to provide it with operating power.

 

[John Williamson]

View attachment 156132

Terminals 1 & 2 are simply a switch. When the Tower is 'on' they are electrically connected together. The diagram shows a permanent live is connected to 'L in' and the switched live comes from 'L out'

3 & 4 (N & L) are for the 230V supply to provide it with operating power.

Thanks so much for this stem. All working perfectly.

One thing I noticed which surprised me when my plumber was servicing the boiler is that both the central heating (upstairs) and underfloor heating (ground floor) are connected to the 230V RT.

In my mind this seems strange but possibly this is normal. I would have expected the two to be separated (possibly connected to the aux relay?). Can anyone confirm?

 

[stem]

If I understand your last post correctly as well as the new Heatmiser RF-Switch (that has replaced the Tower thermostat) you also have another thermostat somewhere else for another heating zone. Although your diagram only shows one 'heating valve' and for two heating zones, there should be two 'heating valves', one for upstairs and one for downstairs.

The boiler 'RT' has to become 'live' if any one of the zones, or the hot water are 'on', otherwise the boiler won't provide them with any heat. So all will be connected to RT at some point. Where the connection is will vary from installation to installation. In the diagram you have posted, I have highlighted the connection of the two wires to the boiler RT with a red circle below. Both the receiver (for the heating) and the Hot water motorised valve are connected to it, so both can start the boiler.

They are isolated from each other by the electrical isolated contacts inside the motorised valve and receiver. So that they work separately, but can both control the boiler when required.