[housemusicfan]

They do make such a thing as an instant hot water dispenser, though they are considered a luxury and not very common:

https://insinkerator.emerson.com/en-us/shop/insinkerator/ins...

[jiveturkey]

These use a tank to keep a few cups of water hot at all times. The instant part is the delivery of it, not the heating. So this does not satisfy the Twinings comment you are replying to.

[appletrotter]

It does, because the water is aerated as it comes out of the faucet.

[jiveturkey]

it doesn't. the faucet of these types of tanks is just a pipe opening and has laminar flow. it doesn't exit the normal sink faucet (which will have an aerator).