Viessmann vitotrol 100 room stat?

[Michael Incorvaya]

Hi there knowledgeable people
Switched boiler off & drained system to remove plastic pipe Pipe work which plumber fitted to rad valves.
Refilled system, turned boiler back on....now the controller, wireless vitotrol 100 will not sync with receiver? Put new batteries & put on test signal mode, on rear of unit....no joy?
When I press the gray button I can rotate through the Water-heating but this leaves them on constant(heating) when I hold the gray button inn the third led lights up yellow & flashes?
Any ideas would be Before£
Can’t find anything on this yellow light, despite going through all instructions & net

 

[plastic_peanut]

Not sure what you get in the kit but my in laws had a similar issue with the Hive thermostat.

This uses a hub connected to WiFi, I had to put the hub, thermostat and receiver all in to learn mode to get them to connect.
I also took the thermostat off the wall and moved it closer to to the hub and receiver.

 

[Michael Incorvaya]

my system dose not work on WiFi. I think it’s a set frequency. Can’t understand why turning boiler of would break it....or is there a sync method?

 

[sxturbo]

Have you pressed the reset button on the unit?