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Hi all,

Last week I was trying to get my OTG running on my Remeha Calenta and Isense thermostat. I didn’t get it to change my room temperature set point unfortunately (the only reason I bought it).
I checked and rechecked the board for errors, but none found; all passive components measured and they are all within tolerance. Only R8 is a small question mark. It says 1k5 in the scheme but parts list claim it’s 1k2. I placed a 1k2, so I guess there’s no issue.

I didn’t check the PNP’s and NPN for I have to take them out first. Also followed the “Troubleshooting” chapter but to no avail. All voltages are within tolerance, only voltage on IC1/17 is 3.19V instead of 3.5V. I ran all the tests using the diagnostic firmware and they also don’t mention any issue.

When I connect the OTG I can see all kind of communication between the thermostat and boiler. Using the monitor program I see all params get filled eventually. But...using “settings” in the monitor program for changing the room temp set point (TT or TC) all that happens is a confirmation of the new setpoint from the OTG. Even after half an hour nothing changes on the thermostat and also my house doesn’t heat up..
When I change the room temp setpoint on the thermostat itself, all just works fine.

I used firmware 3.4 and also gateway-4.0b3.hex. One thing, I have to do a VR=X command. Values 1,2, 5 work, all others result in error 03’s. The OTG reports my Isense (in fw 4.0b3) using the PR=R command, which if fine.
Attached are two logfiles in which I try to change rt-setpoint a few times and then wait. In the other logfile I change the temperature manually on the Isense.

The Calenta and Isense are placed 12/2009, firmware version of Isense is v17 (shows on startup). Maybe it’s too old? I read in http://www.domoticaforum.eu/viewtopic.php?f=75&t=9389 about an option my Isense doesn’t have.
So the big question…how to continue. If needed I can measure signals using a digital scope.

Really appreciate any help on this issue..
Regards, Frank

Did you enable the use of external commands on the iSense? It's mentioned in the manual somewhere, it s in the installation menu of the iSense (i think the menu of the iSense has to be set into advanced/expanded mode first to see the option in the menu to enable external commands)

Thanks for providing the logs. There was another thread where a poster had a similar question, but didn't yet have a gateway to be able to capture logs.

Your logs show that communication works. So there's no need to question the gateway hardware. However, the thermostat never requests an override setpoint. So unfortunately it looks like the absence of the option also means that the functionality is not available.

This narrows down the iSense firmware version needed to work with the gateway. Version 17 and earlier don't, version 19 and later do. Version 18 (if it exists) is still unknown. You could try to contact Remeha to inquire about the possibility to upgrade the firmware. You can also buy a newer iSense version on marktplaats (and then sell yours again to someone who doesn't need this feature).

Thanks pwhooftman and schelte for your answers and analysis!
I aggree the Isense firmware it to 'blame' here. There indeed is no menu option to enable external commands, there's only the 'DIGI ingang'. Easiest step is to buy a newer version and sell the v17 indeed. Upgrading if at all possible by Remeha will leave me without room heating for a while..

Thanks again and Reagards, Frank