Evohome + HGI80 & Domoticz users - zones calling for heat functionality?

OK, now I can admit to putting one of my HR92s in the freezer as part of my testing too :o. I can't even remember now why I did it, although I do remember taking out before I triggered the frost protection and switched on the boiler so I never got to test out whether the frost protection had been disabled. I think I was just too worried that I'd damage it. I noticed too that the latch has to be closed and it prefers the wheel to be attached so that it can complete its calibration. They're great little devices. I now need to think of some more experiments.........

I've updated the Evohome HGI80 code to correctly show the setpoint as Off and this is displayed in the devices list, on the Temperature Sensors page and via any JSON call. Note: this only affects devices created using the 'All Sensors' function as these receive their messages direct from each device rather than via the controller. All the standard devices are unaffected by this change as their setpoints remain at 5deg when the HR92 is set to off. Here's a couple of screenshots:
Attachment 804 Attachment 805

What do you think?

Looks perfect.

hi dan - this looks awesome. not used this tool before but seems like I need to try it, which zone is calling is one of my constant need-to-knows. where do you buy an HGI80 from, from googling all I can find is a german ebay seller? anyone in uk selling them?

Is it possible to use domiticz to tell evohome to do something? in my case, I'd like it use the actuator in an HR92 to open a zone (but not call for heat, if thats possible)
Ian

You can't do that. The only thing you can send to an HR92 is a setpoint, along with the details (temp and time) of the next setpoint. Things like opening and boiler demand are then decided by the HR92 itself.

P.

Yes, Paul's correct. However I have started thinking about a possible solution for this - just theory at the moment. The HR92 could be bound to the HGI80 via the Domoticz code and the HGI80 would be its controller. The HGI80 could also be bound to the Evohome controller via Domoticz and mimic the HR92 and receive/send message to the controller except it would maintain all heat demand requests at 0. I'd started thinking about this functionality as a solution to the similar requirement of being able to monitor & control electric heating zones without triggering boiler demand.

With regards to purchasing a HGI80, the packaging indicates that they are manufactured by Honeywell Germany. I purchased one from a German retailer via web. I can't remember if it was via Ebay.

Dan

The logical conclusion of this path would be for a Domoticz controlled HGI80 to replace the evohome controller altogether.

After all, once configured the controller's main task is to marshall the various variable demands from the HR92s, and create a single heat demand (either TPI style on/off, or Opentherm), and firing valve/boiler relays at the appropriate time. It would be easy to replicate that.

I'm not sure I'd advise it, though.

Hi Paul,

Yes, I don't think replacing the Evohome controller with Domoticz + HGI80 is advisable. The controller is pretty reliable and provides a great, simple user-friendly interface. I'd expect a Pi + Domoticz + HGI80 to have some reliability problems and although it has the potential to offer far more features, will always need a fallback. It's just a potential solution for those that are keen to have greater automation and either enjoy or can tolerate some tinkering.

I've also been unsuccessfully playing with ways of displaying additional information on the controller e.g. might it be possible to show heat demand by sending the values as temperatures and then reverting back to the real temp and repeating this a few times. I'm just playing though and it would be so much better if these could be added as new features to the controller.

Quick update.

The following Evohome HGI80 updates have been merged into the main Domoticz repository:

• Fixed Evohome battery info
• Updated Evohome auto-naming of zones
• Added Evohome 'All Sensors' Off Setpoint

I'm still working on the following items:

• Add functionality to handle installations where there are multiple controllers within range
• Fix identification of all heat demand devices in Opentherm setups
• Investigate periodic corruption of groups of messages
• Investigate full list of recognised commands

Dan

Quote:

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Originally Posted by DanD

Just a quick update to let you know that I've updated the Domoticz Evohome wiki to describe all the new HGI80 functionality available in version 4.5337 beta onwards.

https://www.domoticz.com/wiki/Evohome

Enjoy!

Dan

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Hi all,

This is my first post. I have recently installed an Evohome system and I am running Domoticz on an RPi2 to provide logging. So far, I am very impressed. Unfortunately, the hot weather is now with us so further experimentation will have to wait until the Autumn. I am interested in monitoring zone heat demand to see if the system is behaving correctly.

A few days ago I downloaded the latest RPi beta software from the Domoticz website. It is version 3.5288. I am confused that Dan quotes version 4.5337 beta in his post. Does this mean the the images on the Domoticz website are out of date? If so, where can I get the latest software? A clarification would be most welcome.

Paul