New construction - Energy consumption of the heat pump / electric auxiliary heater

Apart from a written complaint about defects to the heating engineer, I would not do anything here. And then try to recover the additional costs incurred afterwards...

[*]Press and hold the menu button (approx. 5 seconds)
[*]Set the auxiliary heater
[*]There you can, for example, under “general settings auxiliary heater“ try setting it to “turn off auxiliary heater“

We have a Buderus WSW196i (so menu etc. should be similar)

There is 100% something wrong.

Hi Jan,

as my predecessors have already written, something is fundamentally going wrong here. If you moved in on 01.09, what was the meter reading on that day? The screed must have been dried somehow and that definitely requires more electricity. But even then, in my opinion, the division between heating element and compressor does not fit for the mild temperatures.

From the gut feeling, your total consumption for the year should be around 4-5000 kWh. Since you apparently built with a company (general contractor, property developer), I would inform the site manager of the problem in writing and demand a remedy. Afterwards, I would insist on reimbursement of the costs for the additional consumption. If you tinker with the settings yourself, it might be harder later to get the money back or to prove that the system was set incorrectly.

For comparison: We have used about 65 m³ of gas since September 2018, which corresponds to about 700 kWh of heat. If we deliberately assume a not very impressive coefficient of performance of 2.5 for an air heat pump (and it was very warm), this corresponds to about 300 kWh of electricity.

Just google Wärmepumpen verbrauchsdatenbank and click on "Tabelle Verbrauch" on the left side of the first hit. There you will find values from other operators including the house m² numbers.

Thank you to everyone,

my fears were therefore justified. I will primarily discuss it with the construction company.
The meter readings were at 0, the screed had been dried with an external heater using construction electricity before the pump installation.

I am curious how the construction company will react.
Thanks again to everyone.

Other than a written complaint of defects to the heating engineer, I wouldn't do anything here. And then try to recover the additional costs incurred...

Hello,

here I am again. Following your advice, I have complained about the whole matter with a notice of defects and discussed it several times with the heating engineer. It has been confirmed that the bivalence point was set to +10°C and, despite my request to lower it, it is still set at that level. Then I demanded it in writing. I was answered that the bivalence point is not mandatory and that it is a matter of comfort. I also handed over brochures downloaded from the Internet from the company Buderus with recommendations regarding the bivalence point. After further inquiries, I was answered in writing that I should set the bivalence point myself if I know technical matters so well. Is that a statement I should accept? From the "user" level, this is not possible.

From the "user" level, I was able to prescribe a fixed program to the electric auxiliary heater, namely that it should switch on from 00:00 to 23:45 if the outside temperature is below -7°C (recommendation for my location). This reduces energy consumption, although it still remains around 180 kW per week, which is more than expected.

Thank you very much for your opinions.