ᐅ Stiebel Eltron LWZ 504 – User Experiences and Settings

Hello everyone,
we also have a Stiebel Eltron LWZ 504 in operation. Unfortunately, we are struggling with the annual electricity consumption as well. Since we only have one electricity meter installed, I am unable to determine the actual adjusted power consumption of the heat pump.

Brief background information:
KFW 55 house
Built in 2015
175 sqm (1884 sq ft) living space

After ordering a 2-year heating system maintenance through Stiebel Eltron, which was carried out by a service company, we encountered the following problem.

The electric heating element sometimes switches on towards the end of the domestic hot water preparation. It draws 12 kW for about 30 minutes and then turns off again.

The heating technician who installed the system back then cannot perform maintenance and refers us directly to the manufacturer. Therefore, we have not yet had anyone optimize the system settings to suit our needs.

So far, I have tried to adjust the standard parameters as best as possible.

Is there anyone here who is satisfied with the LWZ504 and can help me with the settings, or explain why the electric heating element suddenly keeps switching on again?

Thank you in advance

Steven3003 schrieb:

Stiebel Eltron LWZ 504

Why don’t you turn off the heating element completely?
What is the domestic hot water target temperature? Maybe the heat pump can’t reach the set 65°C (149°F) – just a random figure.

Those would be my first and most important questions. You can always dive deeper later.

The target temperature was 43.3 degrees Celsius (110°F).
However, even though the target temperature had already been reached, the heating element still switched on.

I have now set the heating element to 0 (turned off).

But normally, this shouldn’t happen.

Maybe a thermal disinfection at the end of the cycle?

Regarding electricity consumption, there are simple electricity meters, for example, Shelly 3-phase meters starting from 50 euros, where you don’t need to disconnect anything, just screw it on.

I opened a support ticket with Stiebel Eltron.
A technician is expected to contact me by phone in the next few days.

I’m curious to see what comes of it.