oh nice!
Do you still have some devices?
Hi nils2,
yes and noā¦ Iāll get a new lot (version 0.0.7) around end of the month. I only have a version 0.0.5 left here.
Regards,
Daniel
Oh great!
Are there any functions missing on the 0.0.5, that are available on the 0.0.7?
And how can i order it? I found it here:
but it says, it is out of stock 
Hi Nils,
a new 100 piece batch should arrive soon (first half of November). And already 67 are in waitlistā¦ I find this incredibleā¦
Regarding the Buderus itself, they can do the same. 0.0.6 and 0.0.7 have been mainly assembly adjustments (less THT parts resulting in less I had to solder manually) and things reducing assembly cost in general. I also added an extension header, a direct wire connector and an I2C level shifter (mostly protection) for people that want to extend it by own stuff more easily. But it can do exactly the same with your buderus.
And the biggest change is, that 0.0.7 has no very-low-cost option anymore, because most of it is already assembled. This is, because 90% of my ācustomersā selected the high-end version pre-built (not as a DIY-kit) and this meant a lot of work for me, heating up my soldering iron almost every second day. So I now decided to change the always required parts to SMD and populate almost all SMD parts, including many previous optional features.
In terms of money, this means, that the $34 option does not exist anymore and it will start around $40. But it is always fully assembled now. If there will be bare PCBs of the 0.0.7 is not yet clear. Depends if PCBways sends me some spare PCBs or not.
Regards,
Daniel
Just added myself to the waiting list, I have one question: does it work with the Logamatic 2107 - without the M ?
Hi Mike,
very good questionā¦ I could not say it with 100% certainty, but it seems that the M is the capability to modulate the burner. Mine has an M but also does not modulateā¦ So, 99% it will work. If you would have a look into the control unit, you will see a place, where it can fit in. There are only 2 screws to release and you should see the port on the left side.
In the photo you can see two card edge connectors. The KM271 fits in the longer space (bottom of the picture).
As a last resort, you can send the module back and Iāll refund it.
Regards,
Daniel
Somehow similar questionā¦ Will it work with a Logamatic 2105? From what I can say it looks very similar from inside and have required slot for a card installationā¦
Hi Mirek,
I donāt knowā¦ Most Probably, yes. You could try it and report 
Regards,
Daniel
By any chance, will the item be restocked soon?
I have bought your new version 0.0.7 with ESPhome preinstalled and installed it to my R2107 S0. The board fits perfectly, but nothing happens. I restarted the Logomatic multiple times and also reinstalled the board but no wifi shows up and no lights on the board.
What am I doing wrong or is this connected to not being the M model?
Hi revres,
could you check the Jumper positions? 3V3 and 5V-BUD must be placed.Could definitely be, that I forgot to place it back after final testing with USB supply.
Hopefully it solves your problem.
Regards,
Daniel
I have the same question 
I also have a HS 2105 and installed the module today. So far it just sends WiFi and voltage info via ESPHome to my HomeAssistant. It seems to be detected by the 2105, because I have a new Menu entry called āABGASā which only appears if the km271 is plugged in, but no more data is received and all tries to change a setting wont have any effect. Only switching the LEDs on and of worksā¦ Iāll try to switch to the MQTT firmware during weekend, there ist the 2105 mentioned on github.
Hi all,
actually, it seems, that the S0-versions are a bit different to the M-versions. The Exhaust sensor circuit is independent from my controller part and the 5V is measured by the āmyā controller. It could be, that the S0 has no bus signals or the S0 needs another value for the āsmart moduleā detection.
Iāll investigate it a bit deeper and will come back, as soon as I know moreā¦
Regards,
Daniel
1 Like
Small update; I searched for service manual for 2105 and I found that it is referring to some functions being enabled (as mentioned by Volker) once original KM271 is installedā¦ So there might be some differences, but looks that there is a ālight in the tunnelā, as otherwise it would not make sense to mention this module explicitly. I mean there should be some compatibility on the HW layer, while SW wise it might differ somehowā¦
Hi Mirek,
you are totally right. But information on Buderus units is really hard to get. I would be very happy, if someone that has other derivates e.g. HS2015 S0 or HS2107 S0 could send a picture of their original manual title page. Iām totally lost on Buderus homepage. You can find thousands of mauals for the R2017 M (different revisions/dates), but none with S0.
Regards,
Daniel
BTW: I still have some modules of my last 100 pcs. assembled PCB order (two weeks ago) in stock. But there are not many left.
Iāve just installed the board and it all seems to work!
Some remarks:
- On arrival (see image below), the red jumper was set on 5V-USB instead of 5V-Bud, correct this before installing (I did).
- After adopting in ESP Home via home assistant, a new version was installed which offered heating controls which seemed missing from the original firmware.
- Not yet sure how the interplay works between the thermostat and the km271, but it seems to be able to override it so - so far so good. I cannot override the set temperature of the thermostat nor the temperature the thermostat senses in the room, so thinking about directly controlling the on-off on the boiler and leaving the thermostat knob in a āhigh enough tempā setting.
Hi Mike,
the firmware on the board is a bit older. The reason is, that with a new firmware, I had some problems connecting with the Fallback Hotspot. So I decided to go with the āwell knownā older Firmware that should be relplaced by a custom one, as soon as it is joined with the ESPhome of the user Home Assistant environment and also the configuration should always adapted to your needs. All the imrov stuff can be removed from the YAML to save a huge amount of Flash space.
The āProblemā with a room thermostat is known. The parameters set by the BTU can not be influenced directly with the functionality provided on the KM271 bus. This is a āLimitationā of the Buderus Controller firmware and nothing I can change. But as you describe, it can be circumvented. I have no BTU and the heating system controls the flow temperature. And this can be easily changed by the parameters (offset, target room temperature & āAuslegungstemperaturā) available on the KM271 bus.
Regards,
Daniel
Hi All,
I came across this post and Iām a complete novice. I donāt understand most of what I read in here.
I have a Buderus 2107 controlling my water based heat at a rental property. It has a BFU in the living room and then thermostats with valves in other rooms. I can turn the thermostats off remotely and keep the temperature in the remainder of the house cold when people arenāt there. However, the problem is that the main room is heated always based on what is set at the BFU. Iām told I cannot simply put a valve to prevent new hot water to enter the living room cycle to keep costs down when heat isnāt needed.
Iām looking for a way to basically just turn on āVacationā mode on the 2107 and set number of days remotely when guests leave on a sunday and the house isnāt rented for the next 2 or 3 weeks, so can keep temps at 50F vs 70F.
Does this device allow me to do this or achieve a similar outcome somehow?
Appreciate the help and apologies for the ignorance.
Hi Dre,
basically it could. But you need a WiFi network to connect to and a way to connect yourself to the same network if you want to control it remotely.
Since ESPhome needs some Home Assistant or iobroker Smart Home sytem as a backend, I think the ESPhome does not fit your needs. But there is also dewenniās FW, that provides a WebUI to control almost every aspect of the Buderus. For the vacation mode, Iām not sure, if it can be set directly or for a certain count of days.
Maybe you can ask in the discussions or have a deeper look in the docs.
But as I already said, I see the main Problem with accessing the network at the remote place.
Hope this hekos you.
Regards,
Daniel