Venus water heaters are not good in any aspect neither they heat water efficiently nor they are quick. They its up a lot of energy for heating a small amount of water and that too in almost half an hour.
Just after 3 months use I needed to replace it with the new one because it was causing my bills to soar high. It could be somewhat bigger and much more efficient than it is now design is simple and classic and there are no proper indications whether the water is heating or not service and support centre is very hard to find and the online support Centre gives useless answers to the queries therefore never opt for Venus or you will need to replace after a month or so.