Hi m2ts
This is really interesting, i have the same Genvex setup, and I was wondering if I could make use of excess power from the solar panels to heat the water in the tank?
Do you have any progress in you project?
I’m sorry, but no progress ATM 
. I’m very dissappointed in Genvex. I’ll sum up what the possibilities are:
- Buy a ‘Optima 251 Design’ which costs me 413,82 EUR (TVA incl.). But then I have to have hardware and write my own software to control my Genvex via modbus. And Genvex isn’t very helpfull in case of troubles.
- I have a ‘Genvex data logger program’: it can read data, exported from the SD-card. I should also be able to control the Optima display via an USB cable, but I get a COM error and EEP error. I contacted Genvex, but as you already can imagine: they couldn’t help me (Im sorry, we dont do support for data logger or support for private customers.)
- There already is a schedule under ‘Calender’ for ventilation and space heating. A similar schedule for domestic hot water could be a small step to have a better use of solar energy. This would be the most cost effective as I could keep my current Optima display: just a software upgrade would be required. I’ve send an e-mail to [email protected] at the 23th of January. Things got worse: they even don’t reply to me anymore.
Maybe you can also write an e-mail to Customor Service and to the one who installed or imported your Genvex heatpump in your country. The more ‘voices’ Genvex is receiving, the bigger the chances they do something about it (… I hope).
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@SimLonge, just to let you know that I went for a newer ‘Optima 251 Design’ that includes modbus support. I can control my Genvex and read out values by using a raspberry Pi and a Python script. It costs me a bit more than 200 euro’s instead of 413,82 EUR (TVA incl.), because I could apply for a subsidy in my country if you manage to control heating.
Now I can automatically set the fan on 1 if nobody is at home. Or eg. read out temperatures:
Hello,
I’m glad it’s working for you now.
Where did you get the Modbus table for the Optima 251?
Unfortunately I can’t find these online
Hi moojuiceuk, I am looking for the modbus protocol for my Genvex - do you happen still to have the http://www.n-compass.io/download/documents/Modbus_Communication_OPT250_V3.1_20.11.14_en.pdf file - and will it be possible to send/upload some way for me?
Thank you in advance
Preben Payne, Denmark