ᐅ Setting Up Gas Condensing Boiler Junkers Cerapurmodul ZBS 14
Created on: 4 Feb 2019 21:32
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Goldi09111
Hello everyone,
we need your help or advice again. After living in the house for about 2 months and starting to familiarize myself with the heating system, I noticed that the boiler cycles very frequently, and I can’t really get it under control.
A brief overview of the conditions: we have about 150m2 (1,615 ft2) heated by underfloor heating connected to a "Junkers Cerapurmodul zbs 14/100 s3 ma 23" boiler.
I have set the base point at 27°C (81°F) and the return point at 46°C (115°F). The thermostat in the living room is set to level 4 out of 6, and the temperature is around 21°C (70°F)—not overly warm, but comfortably cozy (occasionally we use the fireplace).
Now, regarding the issue: we have about 100 to 150 burner starts per day. I’ve read from others that they only have about 5 to 10. What could be wrong here? By the way, we have experienced outdoor temperatures ranging from +5°C to -10°C (41°F to 14°F) in the last 4 weeks.
we need your help or advice again. After living in the house for about 2 months and starting to familiarize myself with the heating system, I noticed that the boiler cycles very frequently, and I can’t really get it under control.
A brief overview of the conditions: we have about 150m2 (1,615 ft2) heated by underfloor heating connected to a "Junkers Cerapurmodul zbs 14/100 s3 ma 23" boiler.
I have set the base point at 27°C (81°F) and the return point at 46°C (115°F). The thermostat in the living room is set to level 4 out of 6, and the temperature is around 21°C (70°F)—not overly warm, but comfortably cozy (occasionally we use the fireplace).
Now, regarding the issue: we have about 100 to 150 burner starts per day. I’ve read from others that they only have about 5 to 10. What could be wrong here? By the way, we have experienced outdoor temperatures ranging from +5°C to -10°C (41°F to 14°F) in the last 4 weeks.
So... I’d like to share my experience as well.
Our heating system is unfortunately oversized for our house. This means that if the flow rate is not very high, the water heats up very quickly (too quickly) to the set supply temperature and the system shuts off... this happens so fast that the gas boiler cannot start modulating.
Modulating means that the boiler starts at full power and then reduces its output after some time... but if it switches off too quickly, it can’t reduce its power. The result is constant on-and-off cycling of the boiler.
After extensive reading and testing, I have improved my setup as follows:
- Increased pump pressure to transport the water faster
- Set a minimum cycle time of 8 minutes, meaning the heating only switches on every 8 minutes (domestic hot water is excluded here)
- Then adjusted the slope and offset (offset = desired supply temperature at +20°C (68°F) / slope = desired supply temperature at -20°C (-4°F))
With these changes, I was able to significantly reduce the cycling frequency.
Our heating system is unfortunately oversized for our house. This means that if the flow rate is not very high, the water heats up very quickly (too quickly) to the set supply temperature and the system shuts off... this happens so fast that the gas boiler cannot start modulating.
Modulating means that the boiler starts at full power and then reduces its output after some time... but if it switches off too quickly, it can’t reduce its power. The result is constant on-and-off cycling of the boiler.
After extensive reading and testing, I have improved my setup as follows:
- Increased pump pressure to transport the water faster
- Set a minimum cycle time of 8 minutes, meaning the heating only switches on every 8 minutes (domestic hot water is excluded here)
- Then adjusted the slope and offset (offset = desired supply temperature at +20°C (68°F) / slope = desired supply temperature at -20°C (-4°F))
With these changes, I was able to significantly reduce the cycling frequency.
G
Goldi0911112 Feb 2019 13:40How were you able to set the pump pressure and the cycle lockout?
Goldi09111 schrieb:
How were you able to adjust the pump pressure and the cycle lockout?Settings are in the "expert mode"... press Service + OK button at the same time....???
I need to check again at home...
G
Goldi0911112 Feb 2019 14:41What kind of heating system do you have?
I'm also on a different level for the heating curve, etc. (I had to press the MENU button for 3 seconds).
I'm also on a different level for the heating curve, etc. (I had to press the MENU button for 3 seconds).
Goldi09111 schrieb:
What kind of heating system do you have?
I’m also on a different level for the heating curve, etc. (Had to press the MENU button for 3 seconds).Junkers Cerapurmodul ZBS 22, I looked it up in the manual:
First service level (press and hold the service button (wrench symbol) until it lights up)
Service function 3.A:
Automatic cycle lock
With service function 3.A, when connecting an outdoor temperature-controlled controller, you can activate the automatic adjustment of the cycle lock.
If the automatic cycle lock adjustment is turned off, the cycle lock must be set manually using service function 3.B. Possible settings are:
• 00: off
• 01: on
The default setting is 00 (off).
Service function 3.B:
Cycle lock
This service function is only active if the automatic cycle lock (service function 3.A) is turned off. The cycle lock time can be set from 00 to 15 (0 to 15 minutes). The default is 03 (3 minutes). At 00, the restart depends on the set switching differential (service function 3.C). The minimum switching interval is 1 minute (for single-pipe and air heating systems).
Does that seem correct? I have both manuals at home in paper form, the one for standard users and the professional one, and I always refer to those.
So function 3.A must be deactivated to use function 3.B. There you can then increase the time. Good luck!
G
Goldi0911113 Feb 2019 08:23Thanks for the information. I’ll take a look at it this evening.
Yesterday, around 5:00 PM, I increased the heating temperature from 22 to 23 degrees Celsius (72 to 73.4°F), and as a result, the heating ran almost continuously for 15 minutes and then only cycled on 4 more times until 7:00 PM. Let’s see how it looks this evening in terms of warmth in the house, gas consumption, and the number of heating cycles.
Yesterday, around 5:00 PM, I increased the heating temperature from 22 to 23 degrees Celsius (72 to 73.4°F), and as a result, the heating ran almost continuously for 15 minutes and then only cycled on 4 more times until 7:00 PM. Let’s see how it looks this evening in terms of warmth in the house, gas consumption, and the number of heating cycles.
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