Viessmann Vitrola 200 1 bd Fault.

Ussmak10

Hello everyone,

I'm hoping to get some help with this before I call someone in just in case it's something I can do.  I purchased a house recently.  I saw it in February and the heat was working with the people living in it.  I didn't get to take ownership until June.  I turned on the system and it fired up the boiler, gave me a reading of the boiler temp and everything was sounding good.  Then it gives me a fault and it reads bd.  I was told it's the mixing valve switch not being turned on.  I can't find any switch anywhere for it.  If I move the valve on the box attached to the mixing valve, all the pipes get warm, but nothing ever heats my rooms. 



On a side note.  I have 2 zones.  My second floor is on Zone 1 and Zone 2 is my first.  I have a Vitotrol 300 on my first floor that never connects.  It just does the little progress bar thing.  Any help would be greatly appreciated.  Thanks!