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Temp mixing after Hydroseparator

hot_rod Member Posts: 22,158
You might check out the Viessmann downloads in the "Green" section of heatinghelp. They have some very nice drawings for multiple sources.

In fact most of the Euros have drawings based around 3 way. Check out the stuff at www.solarnetix.com also.

If radiantted reads this he had a wild looking 5 way motorizer mixing device on display at the Foothills Conference. It had a means to blend from multiple sources.

hot rod
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream


  • Paul Rohrs_4
    Paul Rohrs_4 Member Posts: 466
    Reset temp


    1. Plug-n-Play Multiple heat sources such as electric boiler, geothermal, wood boiler,or solar.

    2. I want to provide full reset temp to my secondary zones.

    3. Use of hydroseparator has been authorized

    Would you use a reset controller and proportional mixing valve for the desired effect? That is the way I am leaning at this point.

    Your thoughts?


  • ALH_4
    ALH_4 Member Posts: 1,790
    Multiple sources

    An idea I like (I have not yet had a chance to try it) is to tee a diverting valve into the pipe running between the hydro separator and the motorized three-way mixing valve. Use a differential temperature control to control the diverter valve based on the reset temperature from the system pump and the temperature of the solar storage tank. The boiler just sits there circulating through the hydro separator on its reset curve until needed. That way you still get reset, you save using an extra pump for the solar tank, and the system automatically uses the solar tank if it is warmer than the reset temperature. The solar storage tank could even be a dual coil DHW preheat tank.

    It might not work as well for large heat loads, but it should work just fine for the average residential system. The Vitodens 200 has the mixing valve control included with the boiler. You "just" have to buy the valve and the actuator.

    This could also be done with a wood boiler, or other heat source.
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