Instantaneous boiler

sun_tzu

Hi,
I have an unvented boiler of 210 litres.
I believe is a little bit excessive, given the fact that I have electric heating and I only use it for taking showers and cleaning dishes.

The current process takes 15 minutes to heat the tank for taking a shower and consumes a fair amount of electricity.

I am looking for instantaneous boilers (electric, do not have gas).
Any advice from anybody using them?
Who install these devices? Plumbers?

Any help/advice will be welcomed.

Thanks,
Alex

Thanks,

sun_tzu

No views?

Pincher

Plenty of in-line water heaters out there.

http://www.cnmonline.co.uk/Stiebel-Eltron-Instantaneous-Water-Heater-pr-33373.html

Look at the bottom of the page. Might as well go for the 12kW "DHF12 12.0", since you have to put in a 10mm2 cable whether you go for the 9.6kW or 12kW version.

Personally, I think the existing cylinder will give you a better shower experience. If you have good pressure, the cylinder enables a monsoon shower. A 9 kW electric shower is OK, but not satisfying.

If solar thermal is an option, wait for the RHI subsidy in June 2011. Replace the existing cylinder with a solar compatible cylinder along with solar thermal panels on the roof. Put the Stiebel-Eltron on the output of the solar cylinder. On sunny days, the solar panel has already heated the water to 50 degrees, so the heater doesn't use any electricity at all. Most of the time, the water heater is heating up from lukewarm, which uses less electricity than heating up from cold. On freezing days, you will need to preheat the cylinder using the immersion element to help out.

When you want to have a good monsoon drenching, even 12kW is not enough, so you pre-heat the cylinder to 65 degrees, and enjoy the tropical downpour.

You need to use the immersion element in the cylinder to kill potential bacteria by heating it up to around 70 degrees about once a week. Alternatively,
the Gledhill solar compatible thermal store allow mains water to pass through without mixing with heat store water, so you don't need to bother heating it up. I would go for the thermal store option, with under floor heating loop included, but that's just me.