Steve Freides wrote:
>
> Jim Elbrecht wrote:
>
> > My instant hot water at the sink
> > is plumbed to the cold water line as that's the one with the filter.
>
> That's what we'd do. We have an R/O filter with its own tap at the
> kitchen sink - all the business for it is in the basement on the wall
> right underneath.
>
> We've considered instant hot water in one form or another for years but
> our plumber says it's not ready for prime time even now, in his opinion.
> He recommends it for places like a vacation house but not for a primary
> residence.

You're confusing two different things:

1. Instant hot water dispensers that are typically installed at a sink
and provide ~180F water for drinks and the like.

2. Tankless hot water heaters (gas or electric) that have no storage
capacity and heat regular ~120F domestic hot water only when there is
demand.

Completely different things.