Direct water heating- control issues

[Chri5]

Here's an interesting one.

Client wants me to supply 2 x 3kw electrical loads to run his Ariston STD210 cylinder.

Cylinder is not part of the CH system and was chosen by a 3rd party as a method of getting HW in to the loft shower and bathroom.

Now I could put 2 x event timers across the power supply for control, but I'm not sure of a few things.

* Does this unit use both 3kw heaters simultaneously
* Is there a better method of auto control than 2 x timers

Have looked on Ariston web site, but 95% of the connectivity drawings reference boiler based water heating with the cylinder as a storage vessel. As mentioned the unit will be used as an immersion heater without CH.

Thanks for any interest / help

 

[scaby]

does the building have economy 7 or economy 10? normally the bottom element runs off the economy supply and heats the whole cylinder, and the top element is a top up off the normal supply , its going to be rather expensive to run a 210 litre cylinder on dayrate electricity