It is what you expected, the flow rate goes down to “0” at this time. But the Question is why? And second question is, is this a bad behavior?
At the moment i haven’t activated the ‘Room Temp Controlled’ Option, and there is no heating down time at night.
Yes that’s what I expected. I don’t know why it would do that. Can you also plot outdoor temperature? Is there a reason there is no heating required at that time (too warm outside, scheduled off?). Are you on a tariff where the electricity provider can schedule off-times?
The outside temperature has been below 10°C for the last week and the outside temperature cutoff limit is set to 15°C.
Theree is no tariff from the electricity provider and no hardware that can do that.
My heating schedule is set to 00:00 to 24:00 (in the App) every day, but I don’t think that this takes effect because I have set the heating to ‘Weather-dependent’ in the ‘Senso Comfort’ (Room-controlled is ‘Inaktiv’)
The schedule overrides weather control - if it is off then even if it’s cold enough outside there will be no heating.
Concerning the pauses you’re seeing - are you logging any ebus status messages to see what status the heat pump is in?
I think the hardware is inside the heat pump anyways, it’s just a relais wire or so where the signal to turn off comes in. Where are you located?
Yes, at the Moment I’m using the .csv from JonesPD wich delivers all the necessary data that I need.
I’m from near Cologne
What’s ebusd hmu statuscode scode during that time?
Berlin here 
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I see you have a buffer, it’s like if it heats the buffer and once stopped, it drains all of the heat, making energy integral still going up as water is warmer then the demand and then dropping once buffer is getting colder…
Do you have a scheme of your installation on how the buffer is connected to the system and the secondary circuit?
Hello guys, I am also new here. I apologize because english is not my first language and I hope you will understand what i am asking.
Quick summary of my setup: I have monoblock Arotherm plus vwl 125/6, with buffer 100 l and another 200 l for hot water, multimatic 700vrc, house is 1985 but renovated 3 years ago, 45 m2 of floor heating and 90 m2 radiators.
Before heat pump i had and still have gas boiler, we created hybrid system when temp outside is below -7 so gas boiler jumps and helps heating buffer.
First question, what is lowest modulation compressor could have on my arotherm? I cant find that data, but shelly says 1.45 kw and then it shuts down after reaching target temperature, I hoped it could go lower in maintaining desired temp in buffer without shutting down
Second: I have min flow temp 41 and max 45 in multimatic settings, dont need more than that since temperatures arent low enough so it can oscilate between those two, depends on outside temperature. For ex if flow temp is 43, the heat pump heats buffer until it reaches 43 then shuts down, and starts again when temp in buffer drops to 36-37C, consumtion jumps to 2-2.5 kw to heat water in buffer. Is it possible to reduce that diference when heat pump starts again? My wife works from home and when radiator is 37C she is mad because its cold and it needs time to reheat again?
Here’s the output power data. It should go down to 1kW at minimum modulation, but maybe you need more power to reach your flow temperatures.
I don’t know how the control system works in your specific setup, but typically the Arotherms use the energy integral setting to influence how closely they adhere to the target flow temperature. The hysteresis settings are an additional mechanism on tip of that. You will always have some over/undershoot when you’re outside the modulation range. Of course you could change the hysteresis to something lower but that will lead to shorter cycles and could be bad for COP and compressor lifetime depending on how bad it cycles.
Is the room temperature really dropping when the flow temperature reaches 37°C? There should be quite some thermal inertia in a house so you only experience less than 0.5°C variation between cycles. It might just be that she’s used to an always warm radiator and feeling the direct heat from it when she’s close. This is unfortunately not the best way to work for heatpumps.
Multimatic vrc 700 is in the living room where we have floor heating so room temperature is always around 22 C, her workroom has radiator and everything is fine when temperature in radiator is around 43C but she really feels when temperature drops, i am thinking about changing the radiator to bigger one… You know that saying, happy wife happy life xD
I mean outside temperature is still not below 0 but when it reaches -2 and below, heat pump almost works all day between 1.5-2.5 kw, depending how cold is outside…
Thanks for answering and helping me 
Also advice on getting better way for pump to work is appreciated if you have some for me!
Also tank for hot water, i have once every week program for legionella, some people said i dont need it because water is used often and legionella cant multiply but others say it is mandatory to do it… Temperature for HW through week is 48 and mod is set on balans, is that good?
Haha true! I’m not sure if a bigger radiator would help - if she likes to feel the warmth of the radiator (radiative), then a big 37°C radiator is still at 37°C and she feels less warmth. At 37°C, the radiator gives less than half the radiative power to a human body compared to 43°C, so that’s definitely noticable. Maybe you can put a thermometer in the room to log whether it’s really room temperature or more of a subjective feeling of radiating warmth. In the latter case, maybe one of those planar infrared electrical rads would help.
I also do that, just not exactly once a week as I don’t use the built-in legionella cycle but an automation from Home assistant that changes the target temperature. This way I still get sufficient temperature but don’t have to use the backup heater as the Vaillant legionella cycle. I don’t know how necessary it is, but as I also have a circulation pipe with my hot water that’s not running 24/7 I feel better just blasting those pipes once in a while. 
Here is what the statuscode is during that time
And statuscode says ‘Standby’ (the grey area)
As the ‘Senso Comfort’ tell me it is ‘Systemschema 8’ (Konfiguration FM5 :3) and the buffer is in serie connected between uniTower and Mixer.
Really weird, that’s just the normal standby and no error. How long are those pauses?
Every time about 50 min.
During that time, did you look at the sensoComfort? Typically it also shows some status. Are you logging all of its ebus messages as well?
I don’t know exactly which messages are from the sensoComfort. Next time I will look at the sensoComfort and on the Display from uniTower.
I suspect you are running in “Expanded” room temperature modulation.
In this mode, if the target room temperature is achieved, the compressor goes into “Standby” status, the circulation pump shuts down (hence no flow) and the target flow temperature is reduced.
While in this Expanded mode the integral control still operates. It is therefore possible for the heating to be shut off by the integral reaching 0 deg min. When this happens the compressor status is “Shutdown” and the circulation pump keeps running. (It keeps running at a reduced flow but this may not be apparent if you are running at this low flow rate already.) The target flow temperature also remains high and the integral keeps being added to.
He stated a bit earlier that room control mode is inactive - so that shouldn’t be it.
I think I’ve found a possible explanation.
The buffer tank can only provide a high VLT for the heating circuit for as long as possible if warm water is taken from the top of the buffer and cold return water is returned at the bottom.
The heat pump should not run at all in standby mode when temperatures are above zero or, if there is a risk of frost, reduce its volume flow to the minimum required for frost protection. During the standby time, the buffer memory is emptied and the integral goes to the initial value of -100
I think that could explain the behavior.
during the standby, the flow in the heat pump is maintained even above 0 ( until the TE setting in fact) , at around half the speed
