instantaneous hot water heater

ontheshiraz

We're an all electric household who don't need a tank full of hot water every day. Trouble is, we never know which days they might be so our HeatPlus (like ecomony 7 but with 3 extra hours) immersion heater is either on all the time using the 10 hours of cheaper leccy or switched off for weeks on end and we have to manage with a kettle and the electric shower if we want hot water. We're looking at instantaneous, in line water heaters as an alternative but our trusted plumber isn't familiar with them in domestic use so can't tell us in great detail all the pros and cons of these units when connected (as we think we'd require) one to a bathroom with a hand wash basin and bath/mixer tap and a second unit supplying hot water to a kitchen sink and the downstairs hand basin.
Do any of you have experience of this type of water heater in a domestic environment? Was it something you chose to have installed and how have you coped with it since?
We hope someone on the forum can give us advice on this and look forward to getting their reply.
TIA, ots

lstar337

Instantaneous will cost you a ton more than any time of use tariff hot water.

I'm about to sign off, but search in the energy forum and you will find posts of mine explaining why.

squeekswhenwalking

Have you considered a multipoint running off LPG ( calor) ?

Waldir

Hi ontheshiraz

I am in exactly the same situation as you.
So far, the main problems I gathered are:

- Either you go for an electric water heater with a little tank (such as Aquapoint III 10 Litre 2.2kW, some with smaller tanks), but then you need to keep paying electricity to keep the heat in the water tank topped up (or risk Legionella).

- or you go for a solution without tank (such as this), but then you need high power to get a decent flow:
a few kW would be ok to wash hands, but definitely >5kW for doing the dish and more than 10kW for filling a bath (I currently fill my baths with my 8kW shower, and it takes 30 minutes, so it also depends how patient you are )

The problem with this second solution is that domestic power is usually limited to 100A (when you are lucky, my house is 80A), which is 24kW. So you quickly go over this limit especially if the rest of your house has electric heating + cooking.

Installing 3-phase to get 300A is often possible but expensive (£4k quoted in my case).

Waldir

There is also the cost of connecting those electric+water devices with possibly new RCD entries in the fuse box: I paid £200 for an electrician to connect my last electric shower

Sorry for the pessimistic feedback, I'd also be interested in a good solution!

ontheshiraz

Thanks to those who replied. It seems as though we just have to live with what we have. The immersion is now switched off and is staying off forever!

Cheers, ots.

Waldir

If you're switching it off, and if it is in the loft, maybe it's worth emptying it too, to prevent freezing problems.

southcoastrgi

a kettle & a electric shower for all your hot water needs is this Downton abbey ?
most people use hot water every day

lstar337

ontheshiraz wrote: »

Thanks to those who replied. It seems as though we just have to live with what we have. The immersion is now switched off and is staying off forever!

Cheers, ots.

With a properly insulated tank on a time of use tariff, it costs so little why bother turning it off?

It think you are over estimating what it is costing you. You probably have other household appliances that are costing you a lot more.

Ectophile

What century are we in here? It sounds like something out of the 1930's.

You have cheap night-time electricity and a tank with an immersion heater. If the tank is properly insulated, then you should just be able to heat it up overnight, and it will stay hot all day.

Instead, you want to boil kettles full of water on expensive peak-rate electricity instead.

DREKLY

Why is it not possible to fit a Redring 3Kw instant water heater above the sink, and just plug it into a 13A socket ? I am aware that 3Kw is close to the limit of current draw via a 13 A plug, but this is how they are supplied !
They are around 50 pounds to buy....
Then all one has to do is get a 15mm copper water pipe connected to the cold feed - is that not simple and affordable ???