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Viessmann 222 Heats to room temperature when cold outside, no matter what room temperature set at

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mcbiech
mcbiech Member Posts: 3
edited December 2017 in Radiant Heating
Hello, We have a Viessmann 222 Central Heating System. When I set the room temp to be 18C, all is ok until the weather cools down. Then it brings the room up to 22C no matter what I do. I can set the room temp to 15, no matter, the radiators stay hot until it's 22C. I have looked through the settings to see if there's a weather setting I can adjust, but can't find it. Any feedback?

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  • Paul Pollets
    Paul Pollets Member Posts: 3,656
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    Turn the heating curve down, make sure the night time setback is lower than the setpoint, if you're using it. Read the manual for adjusting the heating curve. I presume you've installed the outdoor sensor?
  • mcbiech
    mcbiech Member Posts: 3
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    Thank you .... Yes, the outside sensor is installed and it's just below freezing outside. The heating curve was at 1.4 ....... I am going to bring it down to 1.1 and see how we do. Thanks very much!
  • Paul Pollets
    Paul Pollets Member Posts: 3,656
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    every .1 turndown usually results in a 3 degree difference in output
  • mcbiech
    mcbiech Member Posts: 3
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    Thanks, I am getting results!