Hi,
Yesterday around 19:00, don’t know why 
, I decided to wire the VR10 on the flow pipe, the “Sytem Flow sensor” and since then I see different behavior on the desired flow T
. Before : it stay constant
. After : it increase during the standby
How System Flow T intervene on the desired flow T ?
I have no buffer
What exactly did you do to your system?!
I have only connect the temp sensor strapped on the flow on the SF1 of my VWZ AI, like Vaillant shows on all their schemes.
I still don’t understand - what is the sensor good for, where did you install it and did you have it before or is that an addition to the system?
My system is hybrid without a buffer, ( Gaz boiler was present and I could keep it for free, it should never kick in, or by -20° maybe… )
so Vaillant scheme is like this with a System flow sensor on the top of the buffer VF1 connected on the VWZAI 12b :
I saw other scheme without buffer where this Flow System Sensor is connected on the main pipe, so I added it there next to the main cut thermostat, it’s at about 5 m pipe from the unit, less then 1 m pipe outside :
About the behavior of the Desired Flow Temp, it’s like it applies the delta between the Flow temp and this Flow sensor on the desired temp, to correct the pipe loss or so ?
Result is an energy integral who’s less impacted during the starts, the first 10 min.
Dunno if it’s better with or without this Flow System Sensor
Interesting setup. What I’m wondering is that after your change you appear to put a lot more power into the house and your average flow temperature appears higher, even though outdoor temperature seems rather constant. Doesn’t your house get warmer now?
I have exactly the same observations and yes, I have the feeling house is getting warmer ( I see sensors tending to go up 0.3-0.4° now , plus I don’t like those peaks in the flow rate nor the heat pump input power , it went up to 800W this morning ! 650W was the max before, I’ll disconnect that ASAP
Now I’m totally confused.
When I checked the behavior of the WP today, I noticed that it suddenly behaved exactly as I had actually expected.
Without me changing anything, it suddenly runs through without the ‘standby’ blocks and the energy integral looks as I expected.
The outside temperature has not changed significantly compared to the last few days.
Interesting, i should see my scheme because i have hybrid system: gas boiler and heat pump. You say you dont have a buffer? In my country Vaillant says buffer is a must for their heat pump so i put it… Dont know if it helps or not
Today is the first day that my system is really having to work. Outside temperatures have been 7 deg or so or lower all day.
I am delighted to see that my rooms are still at the same temperatures, while the flow temps have increased (as expected).
So it seems I have my weather curve bang on 
Is your Vaillant-reported outdoor temp being reported accurately?
Mine is still over-reading by several degrees (5-6deg actual temp overnight, Vaillant temp reading ~9.5deg).
mine is right, you can apply a correction on it in the settings
Vaillant put buffers in all their scheme…
Heatgeek not : Open Loop is the key
Even if both my Heat pump and Gaz boiler 's pumps are running, my system can handle the high flow so it’ll work fine, when under -5, -10 ° ? dunno yet when my gaz boiler will kick in, I’m in TRIVAI mode, it’ll kick in when under 1 or COP 2.25 in my case
Hmm too bad no one around me has same heat pump without buffer so we can compare data. My friend who is 20 km away has installed Clivet heat pump 12kw without buffer (mostly radiators with some minor floor heating) and has no tank for HW and still his pump has slightly bigger consumption but they are diferent pumps…
I was looking before at trivai mode, not sure I understand it too much, my manual doesnt describe it very well so i didnt know how to set it up. Can you choose at what COP gas boiler kicks in?
My only problem is with hot water since my gas boiler doesnt have option for deactivating it… But this has no impact on trivai, just needed to said it because it is frustrating… xD
about Vaillant’s TRIVAI, I found this link which explain it quiet well
https://www.sbz-monteur.de/allgemein/schon-mal-was-vom-trivalenz-punkt-gehoert
You also have to configure in the VRC, it’s all well explained in the manual
I just wanted to follow-up on my previous posts on unstable DHW storage temperature readings, in case it helps anyone. At the time I was seeing fairly small fluctuations and I was putting it down to water mixing effects in the tank. However, I now have better monitoring and also saw some occasional, very erratic readings (see below for a nice example!). It was clear that something was wrong. Anyway, I bought a new Vaillant VR10 sensor (£3.99 on eBay) and it fixed the problem!
Has anyone had to adjust the outdoor temp offset on their SensoComfort? I’ve recently moved the VR20 WC sensor close to my emonPi DS18B20 (they were previously on opposite sides of the house so I didn’t think much of a disparity in readings between them). However, the VR20 (according to the Sensocomfort display) underreads the DS18B20 by a good 2 degrees. On the assumption that the DS18B20 is the ‘golden reference’, I adjusted the Sensocomfort offset up by 2, however it doesn’t seem to have moved the apparent outdoor temp on the display. Does it need a reboot to ‘take’? Seems unlikely…
Using this sensor (VF1) is know to cause overshoot in flow temperature. In UK, Vaillant actively advise people to disconnect this sensor and restart ASHP.
done yeah
Hi @sprajt_88 ,
I’m also hybrid here with a gaz boiler as you know, Now it’s cold, I’d like to test it.
I’ve setting TRIVAI under 1 via the tariff, the heat pump stops in standby mode, but even after 20 minutes, the gas boiler doesn’t start.
Same thing with the bivalence setting. test at -2.5°C outside, Heat. biv. point at 3° & Alt. point on 0. No start of the gas boiler. Any idea ? could you share your settings ? maybe I’m missing something.
Thanks
https://drive.google.com/drive/folders/1-eqngGhbSK6Sw2hXXR9lHGtd_4rViNY2?usp=drive_link
