Setting gas condensing boiler Junkers Cerapurmodul ZBS 14

So... then I want to add my two cents.

Unfortunately, our heating system is oversized for our house. That means if the flow rate is not very high, the water heats up very quickly (too quickly) to the set flow temperature and it switches off... unfortunately this happens so fast that the gas boiler cannot start modulating...

Modulating means that the boiler starts at full power and then reduces it after some time... but if it switches off too quickly, it cannot reduce the power. The consequence is a constant switching on and off of the boiler.

After extensive reading and experimenting, I have now "improved" the following in my system:

- Increased the pump pressure so that the water is transported away faster
- Set an 8-minute cycle lock, which means the heating only switches on every 8 minutes (domestic hot water excluded)
- Then adjusted the base point and end point (base point = desired flow temperature at +20 degrees / end point = desired flow temperature at -20 degrees)

With this, I was able to significantly reduce my cycling.

How were you able to adjust the pump pressure and the [Taktsperre]?

How were you able to adjust the pump pressure and the pulse lock?

Settings in the "expert level"...Press Service + OK button simultaneously....???

I have to check again at home...

What kind of heating do you have?

I am also on a different level for the heating curve etc. (Had to press the MENU button for 3 seconds).

What kind of heating system do you have?

I am also on a different level for the heating curve etc. (Had to press the MENU button for 3 seconds).

Junkers Cerapurmodul ZBS 22, I googled the manual:

First service level (press the service button (wrench) until it lights up)

Service function 3.A:
Automatic pulse lock
With service function 3.A, you can enable the automatic adjustment of the pulse lock when connecting an outdoor temperature controlled regulator.

If the adjustment of the pulse lock is switched off, the pulse lock must be set using service function 3.b. Possible settings are: • 00: off • 01: on Default setting is 00 (off).

Service function 3.b:
Pulse lock
This service function is only active when the automatic pulse lock (service function 3.A) is switched off. The pulse lock can be set from 00 to 15 (0 to 15 minutes). Default setting is 03 (3 minutes). At 00, the switching on depends on the set switching differential (service function 3.C). The shortest possible switching interval is 1 minute (for single-pipe and air heating systems).

Does that fit now? I have both manuals, the one for the regular user and the one for the technician, at home in paper form and always oriented myself by these.

So function 3 A must be deactivated to use function 3 B. There you can then increase the time. Good luck!

Thanks for the information. I'll take a look at it tonight.

Yesterday at around 5:00 PM I increased the heating temperature from 22 to 23 degrees and, lo and behold, the heating ran almost continuously for 15 minutes and only cycled 4 more times until 7:00 PM. Let's see how it looks tonight regarding warmth in the house, gas consumption, and number of cycles.