2 points to this.
1, having a clearer picture of how they work (2 months installed) I feel again the need to warn about them, or rather my vaillant one which is an utter disaster.
2, whether someone can help with a basic setting.
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As I mentioned before, noise inside (not from the nice purring fan outside), is bad enough not just to be intrusive but aggrevating & impossible to live with. Noise eminates from the heat compressor outside > fed