Hot water on demand?

drpete2003

I have a ground floor maisonette and we are currently planning a new bathroom. We are going to rip out the bath and have a shower enclosure as we never use the bath. This would mean that the only other sources of hot water would be the kitchen sink and the bathroom sink. Currently we have a stand-alone immersion heater housed in a small airing cupboard that we switch on and off as needed. We mainly use the hot water for washing up in the evenings and a bit of hot water in the mornings.

My question is this..has nayone ever used or heard of a electric hot water on demand system. These systems would allow me to totally rip out the immersion and give me some much needed extra space. These systems seem to be very popular in the U.S. but not here in the UK? I wonder why as they seem to be a great idea and money saving as the unit only turns on as you need it. My only worry would be the electrics but im sure a decent electrician would tackle the job.

goldbyron

I am not sure if this is the same thing. I had a combi boiler in a flat I used to live in which provided hot water on demand. I currently have a boiler and hot water tank with seperate controls so will have not hot water if it hasn't been on (I have gas heating). My partner also has the water tank which she has to switch on and off (she has electric heating).

My previous boiler was connected to a GCH system so I am not sure if it would be an impediment if you have electric heating. However this must exist in the UK. I am also wondering if a plumber (Corgi) may be better equipped for the job as it would involve connecting to pipes etc. I am no expert on these matters but I think I would contact a plumber in the first instance and enquire. Alternatively you could ring a plumbers merchants shop in your area and ask them if such a unit exists before booking a tradesman.

Ebe_Scrooge

Yes, a Combi boiler is what you need. Pretty common these days, and generally a lot better than they used to be ( i.e they will actually provide more than a slow trickle of hot water ). I've had one in both of my last 2 houses and wouldn't go back to an ordinary system of boiler + hot water tank. We noticed a huge drop in our gas bills since you only heat what you need. The boiler will normally heat both the hot water and the central heating.

The downside is that you'll definitely need a professional to install it for you, and the initial cost will be quite high ( probably around the £1000 mark for the boiler, plus labour, though they do vary enormously in cost depending on what you need ). Having said that, the convenience and on-going savings are a definite bonus. I'm not saying it'll pay for itself in 2 years or anything like that, but it's worth looking at.

I would also seriously consider a maintenance contract, as the other downside that I've come across is that they do seem to be expensive to repair. I've got a contract with a local independant place and it' pretty reasonable - a lot cheaper than British Gas quoted !

will-he-payitoff

You could use an electric water heater for your hot water, do you have electric heating as well?

mikey72

this sort of thing.
http://cpc.farnell.com/redring/45-793201/heater-powerstream/dp/PL00329
needs fitting by an electrician, and can supply up to two outlets, but will be slow supplying both at once.
Same sort of flow as a 9.5kw shower,

drpete2003

Yes mikey72 that is the sort of thing I am after. A combi boiler isn't an option for us as the heating is supplied by a dry warm air system which is located in the middle of the house and it is not connected in any way to the hot water immersion heater.
The reason why i mentioned the U.S. systems is that they seem very popular in the US and the systems appear to be better spec that the UK equivalent. I have been looking at a system called a TEMPRA and it’s made by a German company called STIEBEL ELTRON. They appear to be able to run a whole house off one unit. I was looking at the 20 KW or the 24KW unit as they are designed for a one bathroom house in a cool climate (as the incoming water temperature is a factor in choosing the right model). I would be fascinated to hear off someone who has first hand experience of these systems as they sound brilliant and just what is needed, but I just can’t seem to find a dealer in the UK or anyone that has even heard of one? I am aware that I would need to play with the electrics in the house as the 20Kw and the 24KW units require 2 separate fused circuits but this shouldn’t pose too much of a problem…I hope.

Jonesya

drpete2003 wrote: »

I am aware that I would need to play with the electrics in the house as the 20Kw and the 24KW units require 2 separate fused circuits but this shouldn’t pose too much of a problem…I hope.

I suspect that the reason you don't see them much in the UK is due to the hassle of getting a suitably rated electricity supply - at 24kW the heater would pull ~100A. Most domestic supplies are 60-100A and with no diversity on instant water heaters you may need to upgrade the supply which could be difficult/costly.

MX5huggy

I am not clear do you have gas in the property? Gas is alot cheeper than eletricty for heating water, even more so when you would not be able to use economny 7 etc.

drpete2003

Yes we have Gas in the property it currently only runs the warm air heating and the gas hob in the Kitchin. I don't want to to lose the warm air as its brillient. The hot water is currently supplied by an electric immersion heater which is sited across the hall seperately to the warm air. Its costing us a fortune as most of the hot water is wasted as we only mainly use it for washing up.

I have checked the tecnical data for the instant water heater from the US and it states that the 24KW model runs on a single phase 240v and the max amps is 2 x 50Amps and requires 2 x 60Amp fuses. The 20KW model is single phase 240v and has 2 x 40Amp max load and requires 2 x 50Amp fuses. I have found a manual for the unit, the link is below:-
http://www.plumbersurplus.com/pdf/07637.pdf

will-he-payitoff

To run 2 sinks you should be able to use a 3kw water heater like this
http://www.heatandplumb.com/acatalog/Europrisma_Over_Sink_Water_Heater_3kW_10_Litres.html
Also if you only use the water to wash up why not just boil the kettle?

Canucklehead

Hi

As you have gas in the maisonette I would have thought going with electric would be an expensive way of doing this . Would Rinnai be a solution? The web site does not make it clear that it does a condensing version, but I read that it does in an online report thrown up by Google. Give them a call or email.

Corgi Guy