Vitoden Again

The Wire Nut

In a previous post (<a href="http://tinyurl.com/ya4lo9r">http://tinyurl.com/ya4lo9r</a>) I had some questions and shared some of my travails wiring up a Vitodens 200.



I have substantially completed the wiring and they want to fire it up. SInce I am not familiar with the Vitos, and the contractor's distributor can only answer questions he can look up in the installation book, I now turn to my friends and neighbors...



The Vito (with DHW kit) feeds a low loss header. The supply from the header goes to a Vortech type air seperator and then to a TACO iMixer. The mix output is connected to the input side of the "system" pump. The pump then feeds the various manifolds which are controlled by Uponor (tekmar) t-stats through Uponor zone controllers.



The end-switch output of the zone controllers control a "boiler" relay (the Uponor version of the TACO 501). The boiler relay turns on the "system" pump. The relay also as a set of dry contacts that I am using to signal the boiler to start.



Is this the most efficient way to do this? Can I set up DHW priority? Considering it's a mod/con and I have the outdoor and header sensors, do they need the mixer?



Tired minds want to know...



Alex (Wire Nut) Marx...

Glen Aspen_2

vito 200

the 200 does not need a relay to enable it. with the low loss header - with its supplied temperature probe - essentially controls the firing of the boiler via the programming parameters you choose. the DHW priority is also controlled via the programming - temperatures, time, circ curve all are programmable values. It is all in your installation manual - last time I looked a quick startup guide was also included. Have a look there -  

Paul Pollets

Vitodens 200

The boiler does DHW priority, check the coding in the service manual. I'm not sure why you used an iMixer, the boiler doesn't require a mixing valve after the LLH, unless there are 2 mixed temps required. Typically, the system pump is run by the expansion board, which is added when a LLH is used.  When wiring that pump to the taco relay, you will loose functionality, like pump exercising.



Take the Vitodens class at Viessmann....you'll learn how to optimize the system!

The Wire Nut

Bystander

Thanks Paul and Glen,



I can't claim any of the "credit" for designing this system. It was originally done by an "engineer" then redesigned by the distributor. The original system had a TACO RMB and the distributor changed it to an iMixer amongst other changes.



The distributor provided a basic wiring drawing but neither the plumbing or electrical contractors would touch it. Since I am "The Wire Nut", they called me in to wire it. It wasn't all that difficult in the end, once I got them to pull the correct wires and fix some of the mechanical installation issues.



Unfortunately the manuals were dumped on the boiler room floor, prior to flooding the floor while installing the solar DHW loop!



I know they were missing the DHW expansion kit which was installed, but I gather the expansion board was not ordered as well. Does that go in to the power supply box?



What's the connection between a call for heat and getting the boiler and system pumps going. Does the boiler sense a drop in header water temp and fire to maintain it?



Thanks again for taking the time to respond.



Alex (The Wire Nut) Marx

Paul Pollets

Manuals

Alex, do you need the Viessmann manuals? Do you have a local Viessmann distributor? And yes, the expansion board goes into the power relay module.

The Wire Nut

Manuals...

Paul,



Do need new manuals. I noticed that Viessmann only allows outsiders to download sales and marketing documents, though you can also get the "Technical Manual".



I don't know from whom they got the Vito. I talked to the distributor who "designed" the system, but he was more clueless than I was about all this...



I just left a message for the contractor that hired me letting him know what I've learned. Namely, mixer out, expansion board in. And to get a new set of manuals.



My only other question is how do the t-stats/end-switches (via the Uponor " zone modules") let the Vito know to create heat? Is that also through the expansion board? I currently have it connect to the "request for heat/program change" connections, but I think that's the root of my lack of DHW priority...



Thanks again...



Alex

Simply Rad

Vito oh Vito

Alex



The Vitodens is unique to the market in many ways.  One way is that the boiler works off its owns logic controls and does not require zone valves with end switch's to turn it on.  The boiler is design for a constant circulation control system(TRV's), but will work fine with on/off thermostats. Just make sure you pipe in a pressure by pass valve on the system side of the low loss header   The boiler works off of outdoor reset, meaning system turns on when the OT drops below 68F.  Now turning on means the circulators start and boiler will start on it heating curve.  So just use the Taco control to operate the zone valves and thermostats and do not worry about the endswitchs.



The Vitodens control, the comfortrol has DHW priority ability built into the control. I believe it under coding 2  address  001  and 0B8.  Use must use their DHW production kit which includes an actuator and sensor.  The piping then comes directly off the boiler with designated taps.  Be careful if you are using a non viessmann tank with the smaller Vitodens 6-24/8-32.  Viessmann's innovative design may not play well with others tank.......most tanks have a higher pressure drop through the coil which can cause problems with the on board pump.  



Call Viessmann they will send you manuals



Jeffrey Campbell

Simply Rad

Vito oh Vito

Alex



The Vitodens is unique to the market in many ways.  One way is that the boiler works off its owns logic controls and does not require zone valves with end switch's to turn it on.  The boiler is design for a constant circulation control system(TRV's), but will work fine with on/off thermostats. Just make sure you pipe in a pressure by pass valve on the system side of the low loss header   The boiler works off of outdoor reset, meaning system turns on when the OT drops below 68F.  Now turning on means the circulators start and boiler will start on it heating curve.  So just use the Taco control to operate the zone valves and thermostats and do not worry about the endswitchs.



The Vitodens control, the comfortrol has DHW priority ability built into the control. I believe it under coding 2  address  001  and 0B8.  Use must use their DHW production kit which includes an actuator and sensor.  The piping then comes directly off the boiler with designated taps.  Be careful if you are using a non viessmann tank with the smaller Vitodens 6-24/8-32.  Viessmann's innovative design may not play well with others tank.......most tanks have a higher pressure drop through the coil which can cause problems with the on board pump.  



Call Viessmann they will send you manuals



Jeffrey Campbell

Simply Rad

I am not sure how I became E Burke?

I am Simply Rad

The Wire Nut

Living and learning...

Jeffrey,



Thanks for the input and info. One of the loyal Wall folks sent me the info to access the manuals and I downloaded a full set. Whomever installed the boiler did not leave the set, especially the Quick Start which is a gem...



The more I learn about the Viessmann, the more impressed I am. I hope I have a chance to wire another one!



Thanks again...





Alex...