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Viessmann vitotronic 200 kw2 + Vitola 100

Antoniu Member Posts: 2

Please advise on equipment.

Viessmann vitotronic 200 kw2 + Vitola 100 (old, but serviced and everything works).

I set the DHW temperature to +39C. I set the temperatures on and off: +/- 1K, i.e. I expect the Cylinder primary pump pump to work from + 38C to + 40C. But I see on the screen that the pump works at +41C and +42C. At this water temperature, the burner turns on unnecessarily at + 47-48C of DHW water, apparently only because of the hot water supply, and this is an excessive consumption.

code А2:0 (Without cylinder priority control applicable to heating circuit pump and mixer. Both heating and water heating work)
code 59:1 (+/- 1K)
Code 60 (boiler water temperature during hot water heating) +10K.
Code 61:1 (The cylinder primary pump starts immediately)
Code 62:0 (Cylinder primary pump without run-on)

I control the temperature of hot water through (i).
The burner turns off somewhere at + 51-52C. By inertia, it reaches + 53-54С.

Tried both modes - the same:
1) Top and bottom borders (default +/- 2.5K, I changed to +/- 1K)
2) Adaptive cylinder heating

The pump runs intermittently, still sometimes turns off.

Why did I get there.
Initially, the priority of the DHW was turned on - for the time of heating the water, the heating pump was turned off, and it became cold in the house, because it dragged on for a long time. Initially, the boiler water was set to + 20K. The burner heated the boiler up to + 67-71C.
When setting +39C hot water, the Cylinder primary pump still worked even at +42-43C.

The rest of the equipment works fine, there are no complaints about water.

Tell me - why does not the Cylinder primary pump turn off?


  • Paul Pollets
    Paul Pollets Member Posts: 3,656
    If the water tank reaches 50C., it's working. It may overshoot by 3-5 degrees. If it fails to hold or reach setpoint, the board may be glitching
  • Alan (California Radiant) Forbes
    Could be a bad DHW sensor. It could also be that there's a mineral buildup in the indirect (cylinder).

    Normal DHW temperature is 52°C (125°F). Is 40°C (104°F) better for you?

    Where do you live?
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • Antoniu
    Antoniu Member Posts: 2
    Hi guys,

    I have found the reason:
    code 59:1 is only for the pump turn on in Vitotronic 200.
    So with 39°C: pump turns on 38°C and turns off on 42°C.

    DWH 39°C-40°C is a recommendation of the previous owner.

    My indirect heating boiler is around 400 liters.
    Using +20K ( +57-64C) the speed of heating is 2°C per hour.
    It takes too much time: 2 hours from +39 to +42C.

    It is time to clean the indirect heating boiler?
    The power is too low.
  • Paul Pollets
    Paul Pollets Member Posts: 3,656
    the tank rarely needs cleaning, unless you have hard water. It should be set for 50 deg C. The boiler needs cleaning and service at least every 12-14 months