When Stefan Hagman compared the electricity bill with the significantly larger neighbor's house on the other side of the street, he began to sense that something was not right.

- The neighboring house has 40, while we have 12 apartments.

Despite that, we had almost the same electricity consumption, says Stefan Hagman, chairman of the condominium association Tussilago in Östhammar.

Vattenfall was contacted but denied that there could be anything wrong, says Stefan Hagman.

When Vattenfall replaced the old electricity meter anyway, Stefan Hagman's suspicions were confirmed, something P4 Uppland was the first to report on.

- I started measuring the consumption myself and saw that the consumption dropped by around 60 percent, he says.

Programming error in the meter

There was a programming error in the electricity meter, Vattenfall has stated for the condominium association.

Now the association has received more than SEK 775,000 back.

Money that will come in handy for future maintenance of the house in Östhammar.

- We should not be alone in this problem in Sweden, predicts Stefan Hagman.

Vattenfall has declined to answer SVT's questions, but writes in an email that events of this kind are very unusual.

At the same time, electricity meter errors can never be ruled out.

The company is working to replace electricity meters throughout the country and believes that the new electricity meters are safer.