Why is my water coming out of the tap at 70.1 degrees?

I moved into a new flat in April and my electricity bills have been enormous £90 per month. The hot water is heating to 70.1 degrees. The PulsaCoil (made by Gledhill) booklet states that the temperature should be between 50 and 60 degrees ideally at 52. Do you think this has been installed incorrectly or do I and all the residents (who have the same problem) have faulty Water Storage units. What do you think is the problem.