"Instant" water heaters

Stiebel Eltron seem reliable and regulate the power to the heater so you don't get scalding hot water on low flow. This is my current recommendation for your needs.

Do NOT get Hyco (utter crap that blows elements) or ZIP (blows electronics).

All from personal experience...

I have used the under sink heaters like

Only 2 kW so may not need additional wiring. They use a pressure relief valve so you need to be able to direct any released water to waste.

There are two types of small storage water heater - vented and unvented.

The unvented, unless you can meet particular requirements for the length of cold main for the hot water to expand into, require a pressure vessel whic h is usually an additional and quite signififcant cost.

The vented undersinks use special vented taps, where the knob controls the cold inlet to the heater but the spout is connected to the hot outlet. Beca use of thermal expansion of the hot water these will drip no matter how har d users try turning the knob off (and they will try hard). The taps can als o be expensive.

For occasional handwash where you don't wany any standing losses there are instantaneous handwash spray heaters.

Owain

We had those at work. Tap washers had a very short life because people try to turn off the tap harder to stop the dripping (which it doesn't).

Hmm, might be an issue if water is metered though. also around these parts most who had instant heaters have had problems due to the hard water in London, so this might be a factor as well. Brian

For occasional handwash where you don't wany any standing losses there are instantaneous handwash spray heaters.

Yep. And a kettle for the washing up.

In message , Brian Gaff writes

I plumbed mine into the soft water supply.

Ah which will reduce the volume water requiring to be heated so that

I was thinking that but this is a work place so the elves will say No.

Very hard water supply. :-(

Thanks all.

Simply tedious using kettle for washing up! End of day, two or three mugs to wash. You don't want to have to fill it and wait while you boil the kettle.

Thanks all!

The ones I've seen are available as 3kW or 7kW, the 3kW ones being suitable for running from an FCU, but the 7kW ones needing a 30A feed.

You could consider it an opportunity to install a boiling water tap. They're very useful, but they can also be stinking expensive. Some of them supply boiling water as well as mixing it with cold to deliver "hot" water. We went for a Quooker:

Stinking expensive, as I said. Very nice though.

Jon

Fully fill kettle for last mugs of the day. Use what is left, which will have cooled to safer temperatures, for the washing up. Or if there is not enough left after mugs, refill and boil whilst having mugs. Washing up doesn't have to be done just as you go, can be done when last mugs are finished, not difficult...

Regardless of what mixing facilities it has, I'd be wary of those if it's to be used for hand washing rather than drink making.

They're separate taps.

Still something to catch out visitors or the absent-minded.

Hmmm, said visitors would need to figure out the unusual push and twist action of the boiling water tap. I'm happy with the design of mine. I think the main barrier is the cost; I have no idea why they are so ridiculously expensive.

Because they're used in offices, where works cost is much higher anyway, and cost of specialist parts is scaled up to match what businesses will pay.