On Thu, 1 Apr 2021 08:17:54 +0000 (UTC), RJH
wrote:

On 31 Mar 2021 at 17:45:18 BST, "T i m" wrote:

On Wed, 31 Mar 2021 17:11:54 +0100, Mike Halmarack
wrote:

snip

I think I
would prefer to go for the flash/instantaneous option, even though the
power supply would need to be hard wired.

A mate replaced the 'boiler' type water heater for an instant oversink
type in his shop:

https://www.tritonshowers.co.uk/t30i-handwash

And hasn't regretted it for a second.

It was easy to install, didn't necessitate having to modify the
existing tap feeds and can be run as long / often as he needs (which
has turned out to be quite a lot because it's a shop that's considered
an essential service so open during lockdown and Covid itself).

He said it's at full hand washing temp in about 5-6 seconds but as
it's a spray that's not a lot of water. And that's why I was
interested in something like that as my bathroom hand basin feed is
reasonably long from the multipoint gas water heater, in 22mm copper
(for the bath when there was going to be indirect HW cylinder there)
and whilst we aren't on a water meter (yet), do try not to waste any
if possible.


Thing is, it'd need hot water storage if doing anything other than hand
washing.

Well for my mate in the shop and us at home for the hand basin, as
instant as possible hot water, hot enough to wash hands is about all
we need. Eg, he doesn't do much washing up (just rinses his cup now
and again) as he brings sarnies in from home in a Tupperware box
(trying to eat hot food when running a retail shop on you own isn't
easy).

And unless you can choreograph everything neatly, that's going to
increase running costs a lot.

Oh, sure but see above.

For us we would retain the Multipoint hot water supply so would still
have continuous hot water there if we could efficiently consume the
initial cold (like when running a bath).

The idea does appeal to me - using a combi to heat small amounts seems very
inefficient, wasting water.

That's my main bugbear, especially when it's not been run for a while.

Although the money cost of gas cost is a lot less
than electric (about a quarter).

True, but I also feel guilty about wasting perfectly good drinking
quality water (even though we aren't on a meter). ;-(

If it was the smaller (3kW) one and you could get easy access to both
the water supply (above the sink) and electricity (I have on the other
side of the wall) then if use alongside any existing solution, should
give you the best of both worlds?

Given we now have and are enjoying quite a bit of home automation now
(automatic lights in the hall, landing and kitchen), I think I might
like the idea of an 'automatic' hand wash water heater, subject to
being able to use the existing taps without triggering it etc.

Cheers, T i m