Experience KFW 55 House LWZ 504 Leistung

Hello dear building experts,

we have newly built and moved into our own home in August.
We have installed the LWZ 504, and since the beginning of October the heating operation has also been activated.
Then a series of many problems began that the heating system could not solve, after sitting for days without heating and hot water in the house, the SE service came at the beginning of the week, luckily it is working again.

Now I have been dealing intensively with our new device for a while and I can't shake the feeling that the air heat pump
is too small for our house. If I understand correctly, there are two different strengths of this pump,
A2 and A7 (is that correct?), we have the A2 with 5.16 KW.
However, the manual states that this pump is designed for a capacity of up to 10 KW?

Since we have a very high electricity consumption for me, daily 30 KW for the heat pump (3) people,
I have searched for the KFW documents. Here, a heating load of 9 KW was calculated with hot water.
Also, in the explanation of the heating system it states that we have a system with 9.3 KW capacity.
Could this perhaps have something to do with the annual performance factor being added here?

We have a:

KFW 55 house
Building volume: 1309.04
Useful building area: 419 ( 80 sqm is a granny flat which has a separate instantaneous water heater and a separate ventilation system,
this apartment is heated with our heat pump.
We ourselves live and heat 180 sqm and also have an additional wood stove.
Final energy demand 23.5 KWh, primary energy demand 42.3 KWh

I am somehow confused, am I misunderstanding something here and does the pump attached below
cover the demand? At night it is always louder than usual and the electricity meter runs fast...

I already thank you for your help!

So the area that it has to heat is quite substantial. But size-wise, it is sufficient.

Tell me something about the settings. How often is hot water produced and at what temperature?

How are the individual room controls set?

A2 and A7 (is that correct?), we have the A2 with 5.16KW

The A stands for the outside temperature, the W for the supply temperature, and the sticker indicates which power it produces and requires under these conditions. The power will be sufficient. It is important to heat continuously, so preferably without thermostats. Search online for thermal/hydraulic balancing and heating curve with low supply temperature. If you set that up over the winter, it will run significantly more efficiently than if you leave everything as it is. You can ignore the Energy Saving Ordinance and KfW specifications for heating design. For example, the ventilation system is often forgotten there. We had 7kW there. We calculated 4kW for the heating and the actual value is <3kW.

Thank you very much for your answers, that already puts us at ease. We are already working on the settings, here is our current heating curve

Hot water: we have already lowered it as well, during the day to 40.5 degrees, in the morning for 3 hours and in the evening for three hours to 47.5 degrees, because the heating element was already in use during the hot water circulation temperature. Otherwise, we have a comfortable 21.5 degrees in the house, the bathroom is a bit warmer and the bedrooms are set to 19 degrees. We need to monitor it now, before SE was here it hasn’t run trouble-free for even 48 hours so far. The main cause here was apparently that the volume flow was not right.

When the system was operational again Tuesday evening, the house had 17.5 degrees and in the following 24 hours it felt like a helicopter took off and landed in our basement, obviously it had to heat the entire house again, I thought it would be over soon and it wouldn’t manage it. In those 24 hours it burned a whopping 70 KW, we supported it with our wood stove.

According to SE, all the filters are clogged and should be replaced, I am still waiting for my order, maybe that will also save a few KW.

Thank you very much for your support!

Hey! Change filter after three months? Are they really clogged? We have cone filters in the exhaust air vents, since then there is nothing in the system. What are your settings for the heating curve? Are the values for HK1 and HK2 identical?

Since we have a very high electricity consumption for me, daily 30 KW for the heat pump (3) people,

Whether your house uses a lot or the heat pump is not running efficiently, you can only find out by comparing the produced heat and the consumed electricity. Ideally, you have an external heat energy meter. On the device, you can certainly also read appropriate values. It is important that the heating element does not run as much as possible, the heat pump cycles through and switches on and off infrequently, and the flow temperature is as low as possible (deactivate thermostats, lower the heating curve). You will surely find help specific to your heat pump on the internet.