Viessman Vitrodens 100-W installation advice?

[Bevo111]

Hi everyone.

I'm in the process of having a Viessman Vitrodens 100-W System Boiler installed by a very good friend, who's Corgi Registered but not Viessman trained.

The Installation was going swimmingly until he came to connecting the cylinder thermostat into the boiler. The instruction manual is so vague that after 4 hours of messing about with different possible wiring solutions, he declared himself beat at 6.30pm last night.

Can anybody offer any advice as to how this connect should be made?

The Heating side of the system is running fine but he can't get the hot water side of the system to operate though the cylinder stat.

Viessman Vitrodens 100-W System Boiler
Weather compensator
Digital Timer

Many Thanks.
Phil Beveridge.

 

[JPC]

last one we did we got a cylinder stat (retro fit to existing cylinder) which was put up against the copper side of the sylinder and at the boiler end it when into a red connectot about 6inches down from some wires on the left hand side

 

[JPC]

or was that the weather comp wires....

what seems to be the problem ?

 

[simond]

From memory that is the Viessmann 200 and 300 series using the Viessmann WC system. I don't recall this method being used in the 100 which is a lot more basic.

The wires on the lh side are used for the DHW heat exhanger in the combi versions, and should be connected to the proprietary Viessmann thermistor sensor in a cylinder installation.

However, the 100W series can be used with a mechanical cylinder thermostat. Now that there are two 100 series, pre Oct 08 and post Oct 08 this all gets a bit confusing. I don't know which you have.

 

[Bevo111]

Gents, Thank you for your replys, your help is really appricated.

The boiler is the latet spec available and does not have the same wiring as the wiring diagram on the Viessman website! (i assume that the diagram on the web is for the old spec unit).

The wiring diagram supplied with the boiler, states that the cylinder stat should be conected into the boiler using two wires (marked No.5) on the left hand side of the boiler as you both suggest, however there is an additional external terminal box, should that be used? On conecting or disconecting these wires, the burner ignites and the pump runs, but only for a couple of seconds before the boiler goes into its cool down cycle. The external terminal box has 240v relays located on the board, however the two cables marked No.5 are only 5v. Do you use this terminal box? Does the terminal box require a 240v supply? Unfortunately none of these questions can be answerd using the information supplied with the boiler.

In your answer Simon you say that the V200 requires a Viessman stat, do you think the V100-W require a Viessman stat?

Phil.

 

[HARALIAN]

Give viessman a dingaling int morn

 

[simond]

The two wires are for the external temp probe.

The external relay box is used if you have a third party unvented cylinder, amongst other applications.

The advice to call Viessmann in the morning is good!

You will find the instructions are very poor in detail compared to most other makes; also it is very easy to miss vital components off the order if you are not familiar with Viessmann foibles.

 

[Bevo111]

Gents,

Thank you for your help, I will give the Viessman Technical Department a call in the morning, and i'll post the results to ensure the information is fed back to the forum for possible future questions.

Thanks again.

Phil

 

[Agile]

I suspect this is the latest Viessmann with a built in diverter valve ?

In that case the boiler's own manual should have details of where to connect a cylinder sensor if it supports one (?).

But it also might just preset a higher water heating temperature of around 70°C and just use a single pole cylinder stat.

Without being Viessmann trained you will only get three years warrantee rather than five!

Tony