Electrical Backup For Domestic Hot Water

[davetheglitz]

I've got a customer who is scared of losing hot water with an unreliable combi boiler. His solution is to install an electric shower in his shower cubicle along with his snazzy bespoke shower - and as I'd have to trunk the cable to it due to flat roof and laminate I think it would look awful!

Is it possible to install a 10.8kW instantaneous water heater in series with the combi hot water outlet with some relay logic such that when the boiler is switched off power becomes available for the electric heater?

If not is there any way of operating a combi bypass by operating one switch/valve without any safety issues?

Thanks

 

[ProDave]

There is a make of hot water heater that modulates it's power to provide a constant regulated output temperature. I'll look it up later and post a link.

So it can take anything from cold water to already hot water and just heat it as much as it needs to give the set output temperature.

I am planning to use one on my new house, so we can store the hot water at a relatively low temperature (for better efficiency from the heat pump) and use one of these in line water heaters just to provide piping hot water to the kitchen sink even if the water in the tank is not very hot.

P.S it might just be easier to fix / replace the unreliable boiler?

EDIT

Here's the heater I am thinking of. It's only a link to one on amazon, I don't have time to search for the manufacturers data just now http://www.amazon.co.uk/Stiebel-Eltron-10-Electronic-Instantaneous/dp/B00DSKJ3AM

 

[davetheglitz]

Quite agree about fixing the boiler - but always like to give an option! Thanks for the link - will check it out!

 

[davetheglitz]

Like that idea - but not suitable in this case.

Got this reply from Redring:-

Hi

The unit will not fill a bath, there is not a thermostat as the temperature is flow controlled, meaning in order to supply hot enough water for a bath, the flow rate would be so low that it would take ages to fill, and may operate the thermal cut out.

In order to do this you will need to use a relay for the electric and a diverter valve for the water, as you cannot run hot water from the combi as again it would operate the thermal cut out

Please not the powerstream water heater is only recommended for use on a non-thermostatic standard mixer valve

Regards


Redring Xpelair Group Ltd.

Really hope he just gets the boiler fixed!!!