Electricity bill extremely high due to heat pump malfunction?!

I do see some shared responsibility on your part. As a homeowner, you should take care of your house, and that also includes checking the heating system from time to time. If you don’t do that for almost 3 months, then the construction company, the installer, and the manufacturer cannot be blamed.

Write off the 1000. You will not get them replaced. Bet? For a carton of Bacardi.

So we had a semi-detached house newly built including the land, heating, tiles, and everything else. We were able to make small changes or selections individually; we were only informed about the type of heating system (heat pump). The installation company, etc. was all commissioned by the developer. After completion, we received a brief instruction on the heating system from the installation company, which unfortunately had no knowledge itself and installed this system for the first time. As a layperson, it is difficult for me to determine whether what is said during the instruction is really true or false. At handover, there was no malfunction; this only occurred after about 2-3 months.

As a homeowner, you naturally have the task of taking care of various things, but if everything works smoothly, I do not come up with the idea to check everything. If I had to check everything in the house daily (water pipes/electrical lines/heating/appliances), then I would have to quit my job and sell the house because I would no longer have money, but instead time to check everything.

You phrase "commissioning the construction" -> You were the client. And developer -> you were "only" the buyer.

So what?

As a buyer, it is easier to claim a hidden defect with possible compensation for consequential damages. As the client, you have the problem on your hands. According to current legal practice, you should have recognized the defect promptly, certainly not after months.

In addition, from a warranty perspective, your contractual partner is off the hook, as the problem now seems to be resolved. Consequential damages (operating costs) are regularly not covered by warranty or guarantee.

Whether the average user is even technically capable of this plays, unfortunately, a minor role legally. Either way, if you manage a 50/50 cost split as a gesture of goodwill, then congratulations. For anything else, I see little chance, especially since the damage does not justify an elaborate expert process.

As a homeowner, you logically have the task of taking care of various things, but if everything works smoothly, I don’t get the idea to check everything.

There are many intermediate stages between checking daily and not looking at the heating for 3 months during the main heating period. Especially in the first few years, you do pay more attention to consumption and adjust the heating to your own habits. For me, there were times when I really read the electricity and heating meters every day to be able to track the effects of adjustments. Now I do it on average once a week. Maybe you don’t have to do it quite as extremely as I do, but reading once at the end of the month does make sense. I’m surprised that it didn’t interest you at all.

Hello, it really will be difficult. As a homeowner, you also have responsibilities. Many forget that when they move out of renting. The landlord bears the risk. I can tell you that we always had trouble with the pump the first 2 years. I recorded water and electricity every 2 weeks. Currently every 4 weeks. To detect such irregularities immediately.