No, it extracts heat from the air in the basement. It cools the surroundings (assuming one is using the hot water, not allowing all the heat there to eventually diffuse out through the insulation, but a resistive water heat faces that same issue without having caused any cooling first.)
But in winter, when I’m using more hot water, the heater is cooling a house I’m desperately trying to keep warm? Not sure that’s any better. Is the amount of cooling noticeable? We’re in a small (by US standards), mid-70s home - it’s already next to impossible to keep the basement warm enough to use in January.
