OTGW doesn't connect to boiler?

[ebaauw]

I recently got an OpenTherm Gateway from Nodo-shop, with a NodeMCU Wifi module. The gateway seems to work - I can connect to the OpenTherm Monitor to the gateway over Wifi. With neither the thermostat nor boiler connected, the monitor shows a R00000000 message every second.

When I connect my thermostat, a Honeywell Modulation (with touch screen), it shows the standard startup display to set the date and time. After a couple of seconds the display switches to "aansluitfout" (connection error), and the thermostat becomes unresponsive. The Monitor shows "Thermostat connected" and after that a T00030000 message every second or so. From what I understand from another topic here, this is to be expected when the boiler isn't connected.

However, I see no changes after I connect my boiler, a Remeha Avanta. I don't see any Bxxxxxxxx mesages. Switching between Monitor and Gateway mode doesn't seem to make a difference.

As I said, I connect over NodeMCU - I don't suppose I can load the diagostic firmware over Wifi?
EDITI managed to load the diagnostic firmware over WiFi! On the voltage test (option 5) it reports 0.00 for the Boiler, regardless whether it's connected or not.

Any help is highly appreciated!

[ebaauw]

It was a hardware issue: they mistakenly sent me a test board. I got a new board now which works.

[hvxl]

Glad to hear the problem was resolved. Thanks for taking the time to report that too.

[TomoKRK]

Hello All, I would like to ask for help and/or suggestions how to troubleshoot the issue I have with OTGW not connecting to the boiler.
On the surface, the issue seems the same/similar as reported by the creator of this thread.

A bit of the insights into the current configuration:
1) OTGW with NodeMCU - flashed with latest firmware 5.1 and I am running otmonitor 5.1 too.
2) Boiler - Brink Renovent HR Large/400 - which is actually the same as Wolf, Vitovent etc

All seems to be working fine (connectivity wise) - I mean have access to the gateway, otmonitor is connecting
to gateway too etc. However after I plugged the gateway into the ventilation - Brink stops operating, looks like
some kind of the reset it gets as after few seconds it starts again, however after 1 min more or less the same thing
happens, so in essence ventilation is not able to operate normally with the gateway plugged into the OpenTherm
socket there.

The troubleshooting I have done:
1) Shorted X1 - as I don't have thermostat and I want only to control heat recovery - no change in the behaviour
2) Put the diagnostic firmware in and run some tests - I think only test #1 and #5 returned anything.
for first test of course the leds where flashing in sequence, however the voltage reported was as follows:

15:38:15.979131 Opentherm gateway diagnostics - Version 1.2
15:38:15.990262 1. LED test
15:38:16.017628 2. Bit timing thermostat
15:38:16.042049 3. Bit timing boiler
15:38:16.060100 4. Delay symmetry
15:38:16.081178 5. Voltage levels
15:38:16.095432 6. Idle times
15:38:45.955671 Command (via websocket): 5
15:38:45.963336 Enter test number: 5
15:38:47.161576 Thermostat: 0.00
15:38:48.355930 Boiler: 0.00
15:38:48.373145 Reference: 1.22

because of the voltage reported back I lean towards conclusion it might be something with the gateway itself as author of this thread
reported, however I would like to confirm and explore any other options, suggestions to check before I will contact Nodo Shop.

Here is the example of the sequence from otmonitor log - it's being repeated every minut or so
and each time it starts it stops Renovent heat recovery device - so I assume it's some kind of the reset
however it looks like more asking Brink for status, however there is nothing returned:

Code: Select all

21:49:39.150999  OpenTherm Gateway 5.1   
21:49:39.174909  Thermostat disconnected
21:49:40.123583  R00000000  Read-Data   Status (MsgID=0): 00000000 00000000
                               - CH enable: disabled (0)
                               - DHW enable: disabled (0)
                               - Cooling enable: disabled (0)
                               - OTC active: not active (0)
                               - CH2 enable: disabled (0)
                               - Summer/winter mode: winter (0)
                               - DHW blocking: unblocked (0)
21:49:40.216592  BF0000000  Unk-DataId  Status (MsgID=0): 00000000 00000000
21:49:41.163620  R80190000  Read-Data   Boiler water temperature (MsgID=25): 0.00
21:49:41.304848  B70190000  Unk-DataId  Boiler water temperature (MsgID=25): 0.00
21:49:42.202168  R10010000  Write-Data  Control setpoint (MsgID=1): 0.00
21:49:42.304655  B70010000  Unk-DataId  Control setpoint (MsgID=1): 0.00
21:49:43.234121  R00060000  Read-Data   Remote parameter flags (MsgID=6): 00000000 00000000
21:49:43.327540  BF0060000  Unk-DataId  Remote parameter flags (MsgID=6): 00000000 00000000
21:49:44.274817  R00110000  Read-Data   Relative modulation level (MsgID=17): 0.00
21:49:44.404089  BF0110000  Unk-DataId  Relative modulation level (MsgID=17): 0.00
21:49:44.485143  Command (via relay server, from 192.168.1.5:44740): PR=A
21:49:44.487585  Command (via relay server, from 192.168.1.5:44740): PS=0
21:49:44.524228  PR: A=OpenTherm Gateway 5.1
21:49:44.539831  PS: 0
21:49:45.317118  R001B0000  Read-Data   Outside temperature (MsgID=27): 0.00
21:49:45.410725  BF01B0000  Unk-DataId  Outside temperature (MsgID=27): 0.00
21:49:46.357332  R801C0000  Read-Data   Return water temperature (MsgID=28): 0.00
21:49:46.502822  B701C0000  Unk-DataId  Return water temperature (MsgID=28): 0.00
21:49:47.401193  R900E6400  Write-Data  Maximum relative modulation level (MsgID=14): 100.00
21:49:47.504928  BF00E6400  Unk-DataId  Maximum relative modulation level (MsgID=14): 100.00

I would appreciate any help and assistance here,
Best regards

[TomoKRK]

Hi all, I continue my investigation and learning journey with some progress (actually quite good one).
But first things first, wanted to thank Nodo shop for patience with me and help in assuring that actually
the OT gateway hardware is in tact and functioning properly. Remco - thank you!

The problem which I was facing was related to the fact that in my setup gateway is operating as stand-alone
and actually those restarts of my Brink/Renovent were caused by reboots of OT gateway itself, based on
the logic that if there are more than 64 unidentified messages it gets reset.
Upon further reading of OTGW documentation I have come across the commands which I can add to the execution
sequence when gateway is stand-alone. After adding "AA=70", "AA=80", "AA=82", I started seeing in the logs
ventilation status reports along with inlet and exhaust air temp measures. After it the gateway stopped restarting,
and continued operating for several hours.

The first problem I am seeing is that I can't change the ventilation levels - I am not sure why but Renovent
is not responding to any VS= entries - anybody can help here? I understand that perhaps with the presence
of thermostat that could and probably is working, but how to do it without thermostat present?

The second problem I am seeing too, it's the amount of messages being sent which are not really appropriate for my
setup - I mean pretty much every second there is a sequence of messages with ids (0,1,6,17,25,27 etc) which are
not valid given my setup and are causing a bit of the churn in logs .

The question I have is more related to possibility of making those messages being sent to boiler less frequently
or the ability to turn them off - I do recognise those are important for stand-alone operation when the heating is
being controlled but not for my use case where there is only OT gateway & ventilation/heat recovery unit.
I tried with UI serial command, but it seems there is no effect at all. So any suggestion how to control this aspect
would be greatly appreciated - or perhaps some additional feature request for future to enable that type of
the configurability.

Any suggestions to the two issues above I would appreciate.

[hvxl]

The log you provided here did not show any repeated messages. Can you provide such a log so I can make sure that the OTGW is working correctly? It sounds strange that adding some AA commands would affect such behavior.

Can you also provide a log with the VS commands? Since firmware 5, the same code is used to handle commands, irrespective of whether the OTGW is used with a thermostat or stand-alone.

The OTGW only continues to send MsgIDs 0, 1, and 14, even if they have been marked as unknown. The opentherm spec defines that slaves must support these messages. All the others should stop after 3 Unk-DataID responses, or if you issued a UI command. If that doesn't work, once again, please provide a log.

[TomoKRK]

@hvxl - thank you for your comments, here is the update from my side I have also attached the log file.

A couple of things first:
1) I have re-flashed OT gateway along with NodeMCU to have clean install of 5.1.
2) I have truncated the log file and divided it into two parts separated in the file by comment #REMOVING MsgIDs

Thank you for clarification of the UI command, so if 0,1,14 are expected than it's great, however it still looks like MsgIDs
i.e. 17,25 are showing up in the logs despite sending UI=17 or UI=25.

Now, looking at the log from the start you will see the gateway rebooting every 60 secs or so, and when I queried PR=Q
the response was Q=L. After adding alternate AA=70, you will notice that it starts working flawlessly without any further
reboots. I have added there AA=80 and AA=82.
Now when you search for that comment in the file #REMOVING, there is start of me removing the MsgIDs - so I removed
DA=70, DA=80, DA=82 and after short period gateway started rebooting again.

What's regarding the VS command, through some experimentation I have found out that when I send i.e. VS=1 and then
issue PM=71 (Control Setpoint V/H) it was accepted and the speed ventilation was changing. Perhaps it's the way meant to
be and somewhere covered in the specs if that's the case I have missed that so I need to apologise here.
So I added MsgID 71 to alternative list (AA=71), so now I can issue the VS command and it's affecting the ventilation
speed pretty much immediately.
The other part to this VS story, is the important fact that I also had to unplug the cable from regular contact switch controller
in order for VS command to work. So it looks like when the regular controller is plugged it overrides OT interface - at least it looks
that way, unless I am missing something here.

So for now, I have integrated the control/steering of my ventilation into my OpenHab instance through their standard OT binding
and through the SendCommand channel I can control the ventilation levels - pretty basic but works!
Unfortunately there are no H/V related data exposed in OH for OpenTherm, probably due to very few people
actually using it as the stand-alone for ventilation/heat recovery as it's in my case. So I will try to look into
this as there are number of interesting data points which can be read and exposed i.e. inlet/exhaust temps, filter check etc.

Cheers

[hvxl]

Thanks for the log. It shows that the OTGW is not behaving as intended. I will have to look into that.

The story regarding the VS command makes sense now. The VS command will cause certain information to be populated in MsgID 71. But MsgID 71 is not normally generated in stand-alone mode. So you have to tell the OTGW to send it via the AA=71 command, which you already figured out.

[TomoKRK]

@hvxl - thank you!

And I should have mentioned this in the first place - you have done a great job with OTGW, it's a kind of thing I have dreamed of
for a while before I have come across your website to get an ability to control my Brink/Renovent. So thank you for all what you
do as it is really valuable! I am an IT (software engineering) background person, but all of this happening on the border of software & hardware
is pure magic for me
It's especially important to highlight as I do realise you are doing it in your free time, so hats off and kudos to you!

P.S.Hope moderator will approve this post Cheers!