Connect buderus to velbus vmbts1 and vmbtc1

I Wonder if somebody did already the connections to a buderus logamax gb172-24 by Keeping the buderus thermostat emc35.
If yes how?
Many tanks.


You can connect a normal open contact from a VMB1RY to your buderus GB172-24 on the terminals marked with a switch symbol. Program the VMB1RY as moment control. The VMB1RY is controlled by the VMB1TC and the VMB1TS. See info with VMB1TC and VMB1TS. Do not program your emc35 with a heatingprogram. Programing will be done by VMB1TC. With the emc35 you only control tapwater temperature and max temperature for central heating.

Hope this will help you


Will tryto do it !

Tks Stis,
I would like to have one more info.
why is the RC35 “disable” after the connection of the velbus modules?


Ideal would be to have both running !


Did you already connect your gb172-24 to the velbus annd then the RC35 disable himself? Can you change some working parameters like tapwater temperature or so?
Depends what you want to do.
The RC35 (normaly you put the rc35 in the livingroom on a wall) is connected to the GB172-24 via the buderus bus (normally 2wires for power and 2 wires for data). This mean you can change a lot of parameters via the RC35.

In the rc35 you can also program your heating e.g. 21°C at 7H00, 18°C at 9h00,22°C at 17h00 and 18°C at 23h00 and this from monday to friday. At sat and sunday you can have a other regime.

Now when you program the VMB1TC there is the possibility that the two programs counter each other.
Best pratice is to set tapwater temperature and timing via the RC35 and set max heatingwater temperature, heatingcurve and so on via the RC35.

The wanted temperature in the room is then controlled by the VMB1TS and VMB1TC (program that you have set into the VMBTC).
That mean that the VMB1TS and VMB1TC are your roomthermostat.

If you want to control every room seperate then you need to have valve that opens or closes the pipes to your radiators. You need to have then in every room a VMB1TS.

You can email me for more info on my emailadress.

Tks again for all this info.
I thinkI have to explain to youwhy I would like to use the VMD items.
In this house I have a buderus GB172-24 and the RC 35.
In another house (at 10 meters), I would like to use the VMB item to control the temperature “remotely”. So that without going to the other site, I can manage it.
This is at least one reason I must keep the RC35…

is the other house connected on your GB172-24 or does it has his own one?


So in your own house you set all paramerters and heating times with your RC35. For the second house you want to use the VMB1TC and VMB1TS.

You will need to have a second circuit for heating the second home. That mean you will have to install a second circulationpump and main valve (in your house) controlled by a VMB4RY so that the 1e relay switch on the pump and the 2e relay to open the main valve to the second house. You will have to connect the two houses on the same velbus. In your house setup a pc with velbuslink, VMBUSB or VMBRS module and the VMB4RY. In the second house connect the vmb1TC and VMB1TS to the velbus comming from your house. Now you can control the temperature via the VMB1TC in your second house or via velbuslink from your house.

You have to program the VMB1TS so that the main valve opens and the pump starts.
Hope this is the way you want to control everything

If not, post me a email with phone number if you need more info ( i live in Ghent, Belgium).