UK government hires ‘nudge unit’ to help dispel heat pump myths | Behaviour experts say misinformation shared in media and by other stakeholders is impeding uptake

I am not confused, although maybe my wording was confusing.

My point is, that generally speaking, you can't use water from the same tank to heat your drinking water and to cool your home (because it mixes and the resulting temperature will fill neither requirement). There are of course tons of variants of buffer tanks, and in some cases there are bypasses or there's a physical separation between heating water and (water used to heat) drinking water