Instant water heaters (cheap?)

[dunk]

Hi,

I'm trying to find a replacement for my full-sized, electrically heated, double hot water storage tanks. I have an electric shower and only need hot water for washing dishes and hands, not for a heating system.

I don't have a gas supply to my property.

Can you please advise me of any water heaters that know of that are suitable for placing in areas such as under a sink or in a small cupboard. Ideally I'd like a heater that worked "instantly", in a similar way to the shower.

Is it possible to use an instant shower plumbed to the existing hot water piping? Does anyone have any idea of how much instant heaters cost?

Thanks for your help.

Dunk

[steve]

Dunk

Have a look at the image below, its a Redring Powerstream. An instantaneous water heater which comes in 3 sizes:

9.5 KW at £140.86
10.8KW at £152.40
12KW at £177.43

The unit is plumbed directly into the cold water mains.

Mains water temperatures can vary from 5 degrees centigrade to about 20 degrees centigrade in the summer, with an average temperature of about 12 degrees centigrade. Flow rates therefore vary accordingly 6 litre per minute figures as follows:

9.5 KW winter 6 litres per minute will give 42 degree centigrade
10.8 KW winter 6 litres per minute will give 46 degree centigrade
12 KW winter 6 litres per minute will give 49 degree centigrade

Wiring recommendations:

9.5 KW 40amp Fuse and 10mm cable
10.8 KW 45amp Fuse and 16mm cable
12 KW 50amp Fuse and 16mm cable

[Aiyub]

Where can I get more info on the Redring Superstream product
I live in the East Midlands
Thanks

[Dan]

Ariston do a good undersink, unvented heater...

Check this file out... (page 7)
_________________
Regards

Dan Robinson
Jennings Heating & Plumbing
CORGI - 138845
Email: dan.robinson@blueyonder.co.uk
Phone 0777 5731339

[jonnoturne]

My understanding of the Redring Powerstream Brochure is that the 6 litres/min figures you quoted are the SUMMER temperatures?

They say:
Flow rate - Winter/Summer
... 6lts per min
PowerStream 9.5 ... 28/42 degrees C
PowerStream 10.8 ... 31/46 degrees C
PowerStream 12 ... 34/49 degrees C

I have cross checked this with some US sites that talk in temp rise in degrees F and Gallons per min and it seems to match.

So beware, you may not get the hot water you expect.

Grant@PlumbingPages wrote "It is flowrate. The electric heaters simple cannot keep up a flow suitable for a shower mixer, simply as that!"

Also, Triton wrote to me as follows:
"The 9.5kW instantaneous water heater mentioned we believe to be our
TW10i model.

Should this be correct then we must inform you that this model is solely
for use as an undersink water heater to feed a single tap at a washhand
basin, where the temperature of the water is determined by the flow of
water through the tap, the lower the flow the greater the temperature etc.

The unit would not be capable of delivering sufficient flow at the required
temperature to feed the hot side of a mixer valve. Also the cold direct
mains
supply would dominate in the temperature mixing."

So on the face of it a mixer shower is not a goer with an instant electric heater.

But ... Redring sell a shower mixer and kit (Part# 85793605) for use with their heaters.
And my mates builder swears that his Redring 10.8Kw heater and Redring mixer etc works just fine. Also I reckon you could probably preheat the water to summer temps if you knew what you were doing event though Redring say its a no no.

Electrics can be a bit tricky with the 10.8Kw and 12Kw units though.

Hope this helps anybody.

[amtrakuk]

I have got a Redring Power Stream 12KW after my Gas combi boiler died.

Cost me about 200 for ebay last year. I've goto say Im "happy" with it, obviously its not the same as my gas combi boiler was but it and getting a load of convector heaters worked out cheaper than replacing the boiler.

Anyhow the cold winter we had put it to the test I guess. I have got mine as a "direct replacement" to my combi boiler so its connected to the rising main and the output is connected to the existing hot water pipework.

In the cold winter we had I wouldn't run a bath but, I tried it and after getting the water at the right temp for a bath I only cracked open the tap a tiny bit.

Due to the length of pipe work between the heater and the bathroom upstairs (about 20 ft) it takes a good 30 seconds for the water temperature to stabilize in the bathroom. After about 30 minutes I got enough water in the bath to have a hot bath. On the bath I have a cheap mixer/shower tap. It however was powerful enough to have a hot shower.

I know the powerstream isnt really designed for whole house water heating but I only had one. Now the weather has warmed up I can happily run a bath - this time only taking about 10-15 mins to fill.

You will have to learn to drive it. Turning the hot tap on full wont generate a torrant of steaming hot water, you have to restrict the flow by turning down the tape to the point of it biting closed, I can live with that, but I might still get one for the bathroom for more responsive performance

It isnt a fault with the unit Im just stretching it a bit in the current configuration