Incident Report — OTGW WiFi and ATAG A244EC non responsive

[Aboreon]

Hardware and Firmware Details

• OTGW Model: WiFi version purchased from Nodo-shop

• OTGW Developer: Robert van den Breemen

• OTGW Firmware Version: 0.10.2+50c3ed2

• Firmware Compilation Date: Mar 14, 2023 23:02:12

• PIC Firmware: Available, Version 2.1 (Device: pic16f1847, Type: diagnose)

• Arduino Core: 2_7_4 (Espressif SDK: 2.2.2-dev)

• CPU Speed: 160 MHz

• Flash Chip: 4 MB (LittleFS: 1 MB)

• MAC Address: F4:CF:A2:FA:1A:5A

• IP Address: 192.168.50.22

• Heap Mem (Free/Max): 14584 / 13232 bytes

• Sketch Size (Used/Free): 597664 / 1499136 bytes

• WiFi Network: TSEO (Signal: -65 dBm, Quality: 80% - Amazing)

• MQTT Connected: Yes

• HA Integration: True

• Thermostat Connected: False (this goes to true when the gateway firmware is active

• Boiler Connected: False

• Uptime: 00:22 (h:m)

• Reboots: 26

• Last Reset Reason: External System

Setup Goals

• Final Goal: Inventum EVA thermostat → OTGW → Inventum Spaarpomp → ATAG A244EC

• Current Test Setup: Tado thermostat → OTGW → ATAG A244EC

Just Tado smart thermostat + ATAG A244EC
This works well, I can start and stop the heating by increasing and lowering the temp on the thermostat

Problem Description with opentherm gateway
When using the normal gateway firmware it seems to register the thermostat and gives responses like which to my understanding are correct. Thermostat put messages in the log and on MQTT

Code: Select all

20:23:59.497289	T00390000	Read-Data 	Max CH water setpoint: 0.00
20:24:00.001877	T00390000	Read-Data 	Max CH water setpoint: 0.00

20:43:40.497470	T00240000	Read-Data 	Electrical current through burner flame: 0.00
20:43:40.998797	T00240000	Read-Data 	Electrical current through burner flame: 0.00

20:43:36.999114	T007B0000	Read-Data 	DHW burner operation hours: 0

20:44:43.976385	T80394600	Read-Data 	Max CH water setpoint: 70.00
20:44:44.458994	T80394600	Read-Data 	Max CH water setpoint: 70.00

No boiler messages, if I just swap out the OTGW and connect the thermostat directly this works fine but when adding the OTGW it goes to error C61
From the manual ATAG manual: "C 61 geen communicatie via Z-bus (reset alleen mogelijk door spanningsonderbreking)"
Which means no communication via Z-Bus reset only possible via power interrupt

When I try to do this it go to "normal" operating status but still no response or data from the boiler in the OTtools


OTGW Diagnostics (via https://otgw.tclcode.com/diagnose.html)

Test 1 (LED test):
looks good

Test 2 (Pulse timing):

Code: Select all

90181700  Write-Data  Room temperature: 23.00
505,512,496,1004,495,504,996,1003,496,496,503,504,496,503,496,504,495,504,496,503,996,502,497,1003,496,504,495,504,495,504,496,504,495,504,995,1004,995,503,496,503,496,1004,495,504,495,504,496,504,495,504,495,504,496,504,495,504,995.

Test 3: Bit timing boiler
No output

Test #4: Delay symmetry
Error: Interfaces don't appear to be looped

Test #5: Voltage levels

Code: Select all

Power supply: 3.339 V
Reference: 1.222 V
Thermostat: 0.896 / 1.998 V
Boiler: 0.000 V
Reference voltage setting (0..9): [default]

Test #6: Idle times

Code: Select all

T: 467.114
T: 466.945
T: 466.925

Now what I do not understand or know how to troubleshoot further is why the boiler does not seem to be able to do anything.

Hopefully anyone here has any ideas or tips for me. thanks!

[hvxl]

Test #4: Delay symmetry
Error: Interfaces don't appear to be looped

This indicates a hardware fault of the OTGW or a bad connection, assuming you followed the test instructions and looped the OTGW thermostat terminals to the boiler terminals as shown in the picture below.



Make sure you properly soldered the connector onto the PCB.

[Aboreon]

Hallo Schelte,

Thanks for the response I did not do the looping. However now I did and it still gives the same problem.
I let Nodo solder and flash the otgw.

WhatsApp Image 2025-07-17 at 18.50.30.jpeg (100.3 KiB) Viewed 17 times

result still

Code: Select all

Enter test number: 4
### Error: Interfaces don't appear to be looped

which I gues means I need to contact nodo or any other tips i can try?