Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Connecting a Viessemann boiler to a PC via wet string

I'm about to take the plunge, it's 25 degrees outside, and our boiler has started coming on full pelt from time to time - it's control panel (a Trimatic MC) is probably on it's last legs (or, maybe the temperature sensors, or maybe both, or who knows).

So - I have a plan - the boiler is next to the house server. I can get
decent weather forecasts from the internet. I can probably hook up
some temperature gauges in the house -- I can even fix things so you
dial a number and magic happens (see asterisk for open source PBX).

So - magic all the way, but - one missing link - wet string to go
between the viessmann atola boiler and the PC.

I've found something called a LabJack (labjack.com) - cheap - cheerful
and would look like just the right sort of wet string.

I have 2 thoughts about how to proceed:
1/ the simple route - assuming the boiler is working, then it will
keep it's temperatures at about 60-70 degrees as best I can tell. I
could _JUST_ regulate the motorised 2-way valve. This would (hopefully) be
fairly simple... job done!
2/ the hard way - rip out the trimatic thing all together, and replace
all it's control...

So - my question is - has anybody tried this tomfoolery before? Has
anybody any suggestions - does anybody want to join me for the ride?




  • Supply House Rick
    Supply House Rick Member Posts: 1,404

    I have a new heating system (Weil-McLain Ultra 3) that was installed in mid-May, so it has not been through a winter yet. It has an option so I could attach a remote indicator to show that a lockout has occurred. This does not seem important enough to hook up.

    I would be amused to have a repeater of the control panel of the unit on my computer so I would not have to go out to my garage to see what is going on. I do not see a way to do this that would not involve serious modification of the boiler's electronic controls, and I am reluctant to attempt it.

    In the grand scheme of things, the controls on this unit are relatively simple (even though it is a modulating unit that controls three zones and has external reset) when compared to a computer system. I do not see that controlling the system through my computer would in any way increase the reliability of the system -- to the contrary, I expect. If my computer crashes, and it takes me a couple of days to resolve the problem, do I want my boiler running uncontrolled? Do you?
  • Mark_130
    Mark_130 Member Posts: 2

    Right now, I have zero reliability - and even when it works, it's not exactly very good control - I'd like to take weather forecasts into account !!! (and the time of day, and... and ....)


  • Magnehelic
    Magnehelic Member Posts: 63
    For the right amount of lettuce......I can help

    We are a building automations contractor, and I have developed a little "package" for residential customers who are interested in tracking their systems for "fun" (because the return just really isn't there...........( except for maybe really manager type people that tweak and tweak for 40 years)  For $3000,00 I can set you up with an IP/bacnet router (bacnet is a controls protocol, and for remote access from a pc you need it to be an "interpreter") , software, and a single control module with 6 digital outputs (pumps, boiler start/stop, lights......whatever) 6 universal inputs (contact closure, temperature, pulse.......whatever) and 2 analog outputs (modulating electronic mixing valve or anything else that is modulating)  I will write the programming for you, and if you can give me remote access to your pc from the internet, I can even optimize and provide you annual software updates for 100 bucks a year.  the only other devices you would need are relays (10 bucks), temp sensors (15 bucks) and if you wanna get really fancy, current sensors (50 bucks) (proof of motors running on pumps, combustion fans, whatever).  The software is very user friendly and intuitive (many school districts/office buildings etc use it every day), and can even email your cell phone on an alarm that you can configure.  It will display trend reports, and just about drive your car for you (you know what I mean.... if you can get the utility to give you a pulse meter, it can even track your energy usage).  Any takers?  Probably not huh? 
  • CMadatMe
    CMadatMe Member Posts: 3,086

    They make a Vitotronic Retro Fit kit to replace the old Trimatic for the Vitola. I don't have my book with me but they also have phone/pc modules for the control.
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
This discussion has been closed.