Viessmann Vitodens 100 system boilers

[Solagas]

Went to an installation. It is plumbed in as a four pipe system. there is a 2 port valve on the unvented cylinder. I need a wiring diagram for this. The installer did not leave MI or any litreture. viessmann say they do not have any diagrams except for their own controls. The controls on this system are, Continental Room stats, Honneywell 2 port valve and a little grey box from viessmann which converts 220v to low voltage from the 2 port valve and is connected into the boiler.

The problem I'm having is to get the heating and hot water to run simultaniously. i can only get one or the other. Is it suposed to be like that?

 

[silverback]

As most systems, it is hot water priority

 

[Agile]

The "little box" bypasses the W/C and puts the boiler into maximum flow temp of 74 C for water heating.

But that has to be JUST for water heating as the boiler cannot supply two different flow temps nat the same time!

So what is the fault that you are chasing?

Tony

 

[mysteryman]

You can't get central heating and hot water at the same time. It is a water priority system, as with good modern practice. The reason is so that you can heat the water as rapidly as possible at high flow tempeature from the boiler, and when it changes over to central heating, it can operate at a lower flow emperature, best controlled by weather compensation.