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

[DanD]

Hi,

I've seen a number of people with the Evohome system asking for the functionality to be able to see which zones are calling for heat. I'm working on enhancements to the Domoticz Evohome code at the moment for monitoring and controlling the system via the Honeywell HGI80 usb device. The heat demand messages appear to be sent about every 20 min from each zone and I'd be interested to hear what kind of information people would like to see. Possibly just a flag/icon to show which zones are calling for heat or also adding in the heat demand value?

For those of you with one of the HGI80 devices, a couple of my small Domoticz Evohome bug fixes have made their way into the main pre-release Domoticz code and hopefully they'll be in the next release. In the meantime, I'm working on extending the Evohome functionality in Domoticz and I've just completed testing out the ability to add non-Evohome room temperature sensors as remote temperature sensors and released this update to my development area. I'm now working on being able to monitor the temperatures from all devices within zones where multiple HR92s have been grouped into a single zone. I think this will be helpful with optimising and troubleshooting the setup of these zones or just if you're interested in seeing even more info on what's going on around your house.

For anyone interested in testing out or playing with my updates, here's a link to my github development area:

https://github.com/Evsdd/domoticz

Thanks,

Dan

[DBMandrake]

Although I don't have an HGI80 (yet!) I am watching this with interest. As a techie and a tinkerer I like to know how things work in as much detail as possible so this level of monitoring is definitely interesting.

A heat demand indicator for each zone displayed on the controller and app really should be a standard feature though. Are you listening Honeywell ?? Even a little flame indicator icon in the coloured bar where the override icon appears with 1, 2, or 3 fingers to indicate low (maintenance) medium or high heat demand would be welcome. (And no flame when there is zero demand from that zone)

We know the controller has this information because it receives it from the zones and relays it to the boiler Relay / OpenTherm Bridge to fire the boiler, so why not display it ? Even a DTS92 has a flame indicator when used to directly fire a BDR91, shame that it also doesn't show a flame indicator when it is calling for heat when used as part of an Evohome system.

Trying to diagnose why the boiler relay has come on when no zones are apparently requiring heat is a relatively common situation users (especially new ones) find themselves in - and unless you have an HGI80 there is really no direct way to diagnose this problem without a lot of tedious trial and error.

[DanD]

Hi,

Here's an update on adding the ability to monitor the zone heat demand with the HGI80 and Domoticz. I've completed testing my updates to the code and added the updates to my github development area. All of the zones now appear as switches which show their current heat demand (On/Off and % demand). I've added a couple of screenshots to show how this looks in the switches tab and the dashboard. It's not perfect, but hopefully it a helpful start in being able to monitor which zones are calling for heat. During my testing I noticed that my DHW seemed to be behaving strangely and not switching off boiler demand and hence my other post on the forum.

Demand - Switches.jpg

Demand.jpg

PS If you want to try out the functionality I recommend backing up your Domoticz db before installing just in case you hit any problems.
Dan

[paulockenden]

That's fantastic!

P.

[DBMandrake]

Very very nice!

[DanD]

Thanks.

I've made a couple of updates to the code to fix some small bugs which were causing a duplicate 'DHW Valve' device and also occasionally overwriting the correct status and posted the updates to my Github area. I thought I'd post a little more information on what to expect if you do want to try it out. If you do want to try it out either back-up your Domoticz db or create a separate area on your pi. You'll need to follow the wiki guide on installing from source and start by cloning the git repository:

git clone https://github.com/Evsdd/domoticz.git <folder name>

When you've successfully compiled it, I recommend deleting your HGI80 hardware device and adding it again. I've added functionality to the code to auto-name all the temperature zones after 10mins which makes it a bit less of a pain to set-up. After a few mins you should start to see some additional devices named 'Zone' with the subtype 'Relay' appearing and it can take up to an hour for all your devices to appear as some send very few messages. Here's a couple of screenshots to show what the 'Relay' devices should look like. If you have any zones with multiple radiators & HR92s you'll see a unique device for each HR92 so you may see duplicate Unit values, but with unique IDs.

Zones.jpg

Here's how the DHW, Boiler and CH should look:

Devices.jpg

If you choose 'Add Device' by clicking on the arrow next to each on the devices page they will then appear under the switches tab. You can get a simple graph of the On/Off data over time from the switches tab, but at the moment there's no automated way to produce a graph of the % demand data within Domoticz. You can always grab the data using JSON and then plot in another tool, but it would good to be able to view the data directly within Domoticz.

Dan

[DanD]

Another update.

I've updated the Domoticz graphing code for switch devices so that the zone demand is now shown as a % rather than just On/Off and posted the update to my Github area. You'll need to refresh the cache on your browser if you want to try this out as I made the update to the javascript in Domoticz.js.gz (so no need to recompile for this small update). Here's an example from one zone over the last few hours showing the heat demand values from the HR92:

DEMAND.jpg

and here's the temperature profile for this zone over the same period:

TEMP.jpg

I still need to complete some further testing before I'm ready to request these updates to be merged back in into the main Domoticz code and I'll post an update once this is completed. I also plan to complete the work on showing all temperature sensors and also to investigate whether it's possible to decode the Opentherm messages for those using the Evohome Opentherm bridge.

Dan

[paulockenden]

This is really good work Dan - thank you.

[DanD]

Hi,
Another update which I've just posted to my github area. This time to add some functionality that I've been meaning to finish for a few weeks that adds the ability to create temperature sensors for all devices. This is useful where you have more HR92s or other temperature sensors than the maximum of 12 zones and you've had to group some into a single zone (either a multi-room or single-room zone set-up). If you're interested in seeing the temperature profile of each individual device within the zone then this functionality might be helpful. For example, I have 2 radiators one in each of my 2 bathrooms and these are set-up as a multi-room zone on the Evohome controller. I'm interested in the temperature profile of each radiator in this multi-room zone and how these compare depending on which HR92 I designate as the master temperature sensor on the controller.

Here's how to set it up. Go to the Hardware tab and you'll see a new button labelled 'All Sensors' attached to the HGI80 (you'll have to refresh your browser cache after installing the update)
AllSensors Button.jpg
If you click on this button it will add a temporary dummy temperature sensor with a Unit(zone) number 13 which begins the process of adding an individual zone temperature device for every unique sensor that the HGI80 detects. The dummy device will disappear once the first sensor has been detected and you'll start to see lots of devices with Unit(zone) numbers 13 and higher and labelled 'Zone #' where # is the zone group defined on the controller (the Unit(zone) number is the original zone value offset by 12). If there are multiple sensors within one zone these will all have the same name and Unit numbers, but unique IDs. Here's a screenshot of my 16 new 'All Sensors' devices, one for each HR92:
AllSensors.jpg
and here's my separate list of 12 standard zone devices for comparison which all still function as normal:
AllZones.jpg
Note: if you don't click on the 'All Sensors' button this update has no effect on your device list and it will remain unaffected. If you want to remove the functionality, simply select and delete all these new devices with Unit values in the range 13-24 and the functionality will be disabled. The new devices update their temperatures and setpoints based upon the messages received by the HGI80 directly from the sensors themselves rather than from the controller. You only need to enable the functionality once and the devices will remain and update after each restart.

Here's how the different temperature profiles look for my 2 bathroom radiators in the multi-room zone set-up (after some further checking I think the setpoint differences are just due to lost sensor messages and not due to any real differences in setpoint timings)
Bath1.jpg
Bath2.jpg

Enjoy!

Dan

[The EVOHOME Shop]

and also to investigate whether it's possible to decode the Opentherm messages for those using the Evohome Opentherm bridge.

This would be awesome Dan!

Really good work so far.