Electric water heaters

[S2r]

I am looking at a house, it was built in the 1970s and I don't think anything has been changed since then, there's no gas, everything is electric.

So rather than replace the aged emersion heater / hot water tank as well the kitchen and bathrooms, I was thinking about 'tap' heaters or similar - it'll only need hot water for 2 bathroom sinks and a kitchen one (no bath). It seems to be a bit daft to heat a tank of water for it to then sit there getting cold especially as I won't use that much.

Has any one done this?

[TonyRPH]

Our previous apartment had a 10kW water heater for the kitchen sink.

If you want a decent hot water supply, you need at least 8kW.

Bear in mind that you are heating cold water 'on the fly' hence the requirement for high wattage.

They work on the same principle as an electric shower.

[alfabeat]

We have a downstairs bathroom with no hot water feed, and I really didn't want to run one to it, so I used this:

https://www.amazon.co.uk/Instant-Tankless-Electric...

Just plugs into a 3 pin socket (in a vanity unit under the sink). Works ok. Been reliable. You don't get super hot water on high flow, but fine for washing hands. Not the most elegant of solutions but works and cheap.

[colin79666]

Is there an electric shower or does it run off the tank? The former can be pretty weedy and to upgrade might require new wiring. The latter will probably give a better flow rate. That said if the electrics are still 1970s you will probably want to rewire anyway to get sufficient sockets for the 21st century and to get rid of the old fuse board for a proper consumer unit.

Does it have potential for solar? Heating your water is quite a good way of using excess solar rather than the expense of a battery or the pennies you get for selling back to the grid (which may not be possible or restricted by the DNO).

[S2r]

It's got an electric shower, and the 70s wiring is getting sorted, first thing on the list.

So for the sake of 3 sinks, a new tank seems over the top and my electrician can stick a few more cables in at the same time for individual heaters.

Solar panels and a battery are on the list but someway down mainly due to the lack of funds.

[Bert Cheese]

I'll take the PH shame and admit to be a flat dweller...a happy one albeit which is perhaps hard to comprehend...

On taking the place on I immediately binned the massive (taller than me) Fortic tank installation for a 3Kw Ariston jobby as linked below, installed 6 years ago with no concerns since.
The only obvious area of concern is checking you have sufficient power supply and correct condensate drainage away if anything goes wrong...mine hasn't (3 Kw - bottom connections)
The leccy bills provided by the previous dweller basically halved immediately btw...edit: should have mentioned there is an electric shower, still paying £60 p/m to Octopus at present...rising a bit in the winter as I have E7 Storage heaters too.

https://www.screwfix.com/c/heating-plumbing/water-...

Edited by Bert Cheese on Sunday 26th May 23:48

Edited by Bert Cheese on Sunday 26th May 23:49

[caziques]

In the right time and place instant electric water heaters are great.

A decent shower really needs 10kW, which I think you can use 10mm wire for.

[Rayny]

It's a rare occurrence in this country, though it may become more regular as pipework ages - If you have a burst water main and no water coming in to the property, you will be glad to have a full tank of tepid water.
The Hastings area recently had 4 or 5 days without water.
My immersion heater tank enabled me to live, without having to queue up and block the roads to the bottled water stations.

[Unreal]

I only use this manufacturer. Instant hot water heaters. No stored water..

Not the cheapest but never had a problem.

https://www.stiebel-eltron.co.uk/en/home.html

Edited by Unreal on Monday 27th May 12:51

[RizzoTheRat]

I have a Daalderop "Close-In-10" in the kitchen. It's 2.2kW with a 10 liter tank, and is plenty big enough for a sink full of hot water for the washing up. I've never yet run out of hot water and it's very well insulated, the cupboard under the sink is no warmer than the rest of the kitchen. They're really common over here, we have the 15 litre version in our office kitchen.

A quick calc suggests it should take around 16 minutes to heat 10 litres of water from 10 to 60 degrees.