OTGW plugin - odd behaviour
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manjh
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OTGW plugin - odd behaviour
I moved from my old Domoticz/Raspberry installation to a new setup, and also installed OTGW.
It works, but for some strange reason I see odd values, for instance the "Return water temperature" is fixed on 0 degrees.
I can see in the devices tab that it is updated regularly, and I am quite sure the return pipe is hotter than zero.
What could be wrong here?
In the old setup there was a more valid value!
It works, but for some strange reason I see odd values, for instance the "Return water temperature" is fixed on 0 degrees.
I can see in the devices tab that it is updated regularly, and I am quite sure the return pipe is hotter than zero.
What could be wrong here?
In the old setup there was a more valid value!
Hans
- waltervl
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Re: OTGW plugin - odd behaviour
What does Domoticz log say when a value is received?
From what version of Domoticz did you upgrade. The firmware of OTGW in newer Domoticz versions needs to be min 5.x
https://wiki.domoticz.com/Opentherm_Gateway_OTGW
From what version of Domoticz did you upgrade. The firmware of OTGW in newer Domoticz versions needs to be min 5.x
https://wiki.domoticz.com/Opentherm_Gateway_OTGW
Domoticz running on Udoo X86 (on Ubuntu)
Devices/plugins: ZigbeeforDomoticz (with Xiaomi, Ikea, Tuya devices), Nefit Easy, Midea Airco, Omnik Solar, Goodwe Solar
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manjh
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Re: OTGW plugin - odd behaviour
Log doesn't say much:waltervl wrote: Wednesday 14 January 2026 19:47 What does Domoticz log say when a value is received?
From what version of Domoticz did you upgrade. The firmware of OTGW in newer Domoticz versions needs to be min 5.x
https://wiki.domoticz.com/Opentherm_Gateway_OTGW
Code: Select all
2026-01-14 21:29:26.459 OTGW: Temp (Return Water Temperature)
Is there a simple way to find the firmware version?
Hans
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manjh
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Re: OTGW plugin - odd behaviour
My OTGW carries an ESP unit to communicate with the Domoticz server. When I log on and look at the log, I see:
What does this mean?
Code: Select all
v14078825 : Ser2N: serial buffer full!
Hans
- waltervl
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Re: OTGW plugin - odd behaviour
That the serial communication to Wifi is not working correctly. But better check that with OTGW specialists...
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azonneveld
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Re: OTGW plugin - odd behaviour
Use the OTMonitor to connect to your OTGW. Using that tool you can also update your otgw firmware.
https://otgw.tclcode.com/download.html (near the bottom of the page)
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manjh
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Re: OTGW plugin - odd behaviour
I installed the tool. When I connect to the OTGW, all I see is a message like this:azonneveld wrote: Friday 16 January 2026 7:43
Use the OTMonitor to connect to your OTGW. Using that tool you can also update your otgw firmware.
https://otgw.tclcode.com/download.html (near the bottom of the page)
Code: Select all
07:10:22.227794 SEHans
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azonneveld
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Re: OTGW plugin - odd behaviour
Okay, so your connection is established, but not working.I installed the tool. When I connect to the OTGW, all I see is a message like this:Use the OTMonitor to connect to your OTGW. Using that tool you can also update your otgw firmware.
https://otgw.tclcode.com/download.html (near the bottom of the page)To make sure, I also disconnected the HW in Domoticz, does not mke a difference. When I keep the HW enabled, I can see error messages in the log, so the OTMonitor is connected...Code: Select all
07:10:22.227794 SE
I dont recognize that code but it seems to be a problem with de OTGW or ESP.
Try a powercycle on the OTGW, if that doesnt work, try reloading (or update) the ESP firmware.
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manjh
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Re: OTGW plugin - odd behaviour
I already tried re-booting several times over the past weeks.azonneveld wrote: Thursday 22 January 2026 22:20Okay, so your connection is established, but not working.I installed the tool. When I connect to the OTGW, all I see is a message like this:Use the OTMonitor to connect to your OTGW. Using that tool you can also update your otgw firmware.
https://otgw.tclcode.com/download.html (near the bottom of the page)To make sure, I also disconnected the HW in Domoticz, does not mke a difference. When I keep the HW enabled, I can see error messages in the log, so the OTMonitor is connected...Code: Select all
07:10:22.227794 SE
I dont recognize that code but it seems to be a problem with de OTGW or ESP.
Try a powercycle on the OTGW, if that doesnt work, try reloading (or update) the ESP firmware.
But why would that work I can see many valid values coming into Domoticz from the same device. Connecting from the Windows OTMonitor does not yield anything. And yes, I did disconnect the Domoticz HW entry before trying that.
Hans
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azonneveld
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Re: OTGW plugin - odd behaviour
What firmware are you running on your ESP? (espeasy, tasmota, etc?)manjh wrote: Friday 23 January 2026 23:53 I already tried re-booting several times over the past weeks.
But why would that work I can see many valid values coming into Domoticz from the same device. Connecting from the Windows OTMonitor does not yield anything. And yes, I did disconnect the Domoticz HW entry before trying that.
What does the webinterface of the ESP shows you?
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manjh
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Re: OTGW plugin - odd behaviour
It runs ESPEasy, build 147.azonneveld wrote: Sunday 25 January 2026 17:28What firmware are you running on your ESP? (espeasy, tasmota, etc?)manjh wrote: Friday 23 January 2026 23:53 I already tried re-booting several times over the past weeks.
But why would that work I can see many valid values coming into Domoticz from the same device. Connecting from the Windows OTMonitor does not yield anything. And yes, I did disconnect the Domoticz HW entry before trying that.
What does the webinterface of the ESP shows you?
Not sure what you mean by the Web interface. When I log on to the unit from a browser, I can see the usual info. THe one thing that stands out is the errors in the log:
Code: Select all
1020965753 : Ser2N: serial buffer full!Hans
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azonneveld
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Re: OTGW plugin - odd behaviour
Webinterface: open browser, enter <ESP-IP:80>.manjh wrote: Monday 26 January 2026 10:09 It runs ESPEasy, build 147.
Not sure what you mean by the Web interface.Code: Select all
1020965753 : Ser2N: serial buffer full!
You should see a webinterface.
That might provide some log (not sure on the old version).
If not, you can upgrade the firmware of your ESP using https://td-er.nl/ESPEasy/ (Chrome/Edge only)
(take out the esp of your OTGW, connect to computer)
Or: perhaps consider buying a new OTGW, which has lots of improvement: https://www.nodo-shop.nl/nl/ons-assorti ... ilder.html
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manjh
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Re: OTGW plugin - odd behaviour
Thanks, that webinterface is the one I was using.
Upgrading the ESP software sounds OK, except that I run the risk of an inoperable OTGW, which makes my heater go down. (Complex story, has to do with the combination of an Insmart remote monitoring tool with the Honeywell T6 thermostat, Known problem, Insmart is working on it).
I guess going for a new OTWG device sounds safe. I will check with Remco.
Upgrading the ESP software sounds OK, except that I run the risk of an inoperable OTGW, which makes my heater go down. (Complex story, has to do with the combination of an Insmart remote monitoring tool with the Honeywell T6 thermostat, Known problem, Insmart is working on it).
I guess going for a new OTWG device sounds safe. I will check with Remco.
Hans
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manjh
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Re: OTGW plugin - odd behaviour
OK, I am now the proud owner of a brand-new OTGW unit.
Works great, but I have a question about the "Return water temperature".
In Domoticz a temperature device shows up, with value 0 celsius, not a very likely value compared to tht Boiler water temperature of 33,1 celsius.
You'd expect something higher than 20.
On the OTGW, I use a LAN interface, and loaded the special OTGW firmware written by Robert van den Breemen.
When I look at the values that this unit receives, the return water temperature is not in the list at all!
So where does this device come from? Is it made up by the OTWG plugin?
Works great, but I have a question about the "Return water temperature".
In Domoticz a temperature device shows up, with value 0 celsius, not a very likely value compared to tht Boiler water temperature of 33,1 celsius.
You'd expect something higher than 20.
On the OTGW, I use a LAN interface, and loaded the special OTGW firmware written by Robert van den Breemen.
When I look at the values that this unit receives, the return water temperature is not in the list at all!
So where does this device come from? Is it made up by the OTWG plugin?
Hans
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azonneveld
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Re: OTGW plugin - odd behaviour
Nice that your new device is working!manjh wrote: Friday 06 February 2026 16:54
So where does this device come from? Is it made up by the OTWG plugin?
Return water temperature is one of the normal outputs of the OTGW. But since no data is given by your boiler, it remains zero.
RWT is not an output for every boiler.
Maybe your boiler is included in the matrix.
That indicates what data is available for each device.
Perhaps your device can also present the waterpressure
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manjh
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Re: OTGW plugin - odd behaviour
Water pressure is there, return water temperature is not. The matrix shows X...azonneveld wrote: Friday 06 February 2026 22:57Nice that your new device is working!manjh wrote: Friday 06 February 2026 16:54
So where does this device come from? Is it made up by the OTWG plugin?
Return water temperature is one of the normal outputs of the OTGW. But since no data is given by your boiler, it remains zero.
RWT is not an output for every boiler.
Maybe your boiler is included in the matrix.
That indicates what data is available for each device.
Perhaps your device can also present the waterpressure
Hans
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azonneveld
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Re: OTGW plugin - odd behaviour
Was it there before you upgraded?
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manjh
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Re: OTGW plugin - odd behaviour
It was there, but had a very strange value (over 100 degrees)...
Hans
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azonneveld
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Re: OTGW plugin - odd behaviour
For measuring the boiler's in and out temperature, I use an ESP with DS18b20 sensors, tie-wrapped to pipes.
You can attach multiple sensors to 1 ESP.
https://espeasy.readthedocs.io/en/lates ... 18b20.html
You can attach multiple sensors to 1 ESP.
https://espeasy.readthedocs.io/en/lates ... 18b20.html
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manjh
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Re: OTGW plugin - odd behaviour
I know, I have used ESP based temperature sensors quite a bit, but now moved to Zigbee sensors.azonneveld wrote: Sunday 15 February 2026 15:52 For measuring the boiler's in and out temperature, I use an ESP with DS18b20 sensors, tie-wrapped to pipes.
You can attach multiple sensors to 1 ESP.
https://espeasy.readthedocs.io/en/lates ... 18b20.html
But it is actually a good idea, I think I still have one ESP lying around somewhere with three DS18B sensors. I'll install them later this week.
Again, good idea, thanks for bringing it up!
Hans
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