Viessmann question?

Derheatmeister

If you are comfortable and the system keeps on running you may have to read into the controls and may have to readjust the Curve/ shift or the WWSD
How long ago was this system installed?

Which control are we talking about? How was it setup? TRV's or Zonevalves? Hydro separator?

airman

Viessmann question

Could anyone tell me why my circulator pump rarely (if ever) shuts off. I have indicator lights showing that none of my zones are calling for heat, nor is the water heater (indirect) calling either. The temperature was 55 today, all the zones were satisfied for hours, yet the pump just keeps on pumping. Is there a setting that would shut it down. It would seem like a waste of energy no?

joel_19

?

What boiler and what controll need more specifics

airman

Viessmann

It is a Vitodens 200 (WB2-8-32). I have a temperature sensor outside. It been up and running for about 5 months. The zone control modules only let the thermostats turn on valve actuators on the radiant manifolds and not the boiler (there is no TT which is what I'm most familiar with). There are 4 radiant zones and the system uses a Low loss header. Also, the pump is very noisy. I'm thinking of changing it to a Wilo with the sensors.

Simply Rad_5

Vitodens


Your Vitodens comes factory set for constant circulation, until the outdoor temperature rises above 70F(warm weather shut down). You should look at adjusting the heating curve first(slope and shift and design temp.) Even at 55F outside air temp some of your house still needs alittle heat, and the curve will adjust for that.

Now for the pump, which pump is loud your boiler pump or your system pump. If, its your system pump, do you have a bypass?

Jeffrey

Derheatmeister

WWSD/Cruve

Like jeffey said the Vitodens comes with constant circ but the WWSD can be adjusted on the front sun and moon dails

You may adjust the curve first and then depending on how thigh your house is you may adjust the Sun/moon dail which is as prev mentioned the WWSD and your circ..

airman

Viessmann

The house is pretty tight. Double pane glass on all windows, storm doors with stripping, most of the house is R-19 with some areas at R-22. The noisey pump is the system pump and I do have a PDB valve on the end of the supply manifold. I never set the "curve" so I assume its running constant. So, just so I'm understanding correctly, I would have to set the curve (slope & shift & design temp).
Even though constant circulation would work best, I have too many devices shutting off zones when satisfied, and at times when the rooms T-stats all shut down I have this primary system pump working sometimes for hours before a zone calls. I guess I'll dive back into the manual to fine tune. The only thing I thought would make sense would be for the zone controllers to communicate with the Viodens to shut down the pump.

Thank you for your time!

Rudy

Derheatmeister

Happy system....

I do not know what kind of Radiant emitters you have i.e. Plateless Stapleup,Plated stapleup, in gip,Panels/Rads. but the instructions give you a idea of depending on the above mentioned what your curve shall be at... what is it set to now? and is the house comfortable? what are the surface temps? and what kind of flooring do you have i.e. Wood flooring does not like temps over 80F and carpets do not like Temps over 87F!

Try heating the house with the lowest Curve possible!
then adjust you "WWSD" again to the lowest possible setting i.e 66F to 68F depending on the R value/Solar gains/ other heat sources,that will turn your "Boiler Circ" off then the outdoor temp is within a couple degrees of the "WWSD"
also adjust your PDB so that your circ is not "Deadheading" the sensor on the Low loss will sense the "System temps" and modulate the boiler according to your adjustments to the Curve/shift
You must feel the System or be one with the system...
Read instructions,Listen,feel,sense,ask,adjust... Readjust... and you can balance it to make it a "Happy" system working in harmony... Good luck. Richard

Paul Pollets

Too many zone valves...

Too many zone valves can affect the performance of the modulating boiler. The Vitodens, like most mod-cons is designed to work at constant circulation with variable flow and variable temperatures. When the zone valve closes, the heat to the zone stops, and the whole purpose of constant circulation is defeated. There should be a pressure bypass differential between the zone pump and the returns when ZV's are used. We try and minimize ZV's when using mod-cons. When using radiators, it's preferred to use TRV's to control setpoint, rather than ZV's.

This article explains it best:

http://www.comfortableheat.net/pdfs/continuous.pdf

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Unknown

the quick response is, if you set the curve aggressively, your zones will shut off less because they will be more 'starved' for output, and the boiler can then really do what it was built to do.