I can’t see any way to use the Medium speed through the modbus interface either, so I don’t think I’ll be able to solve this for you through Homey . There is a user fan speed option control register, but that’s only for AC and not the EC fans.
Hey @kjeet90 ,
From looking at the control registers and messing around with the remote a bit further, I think I know what’s going on here. I think the 0x registers are to toggle certain modes on the device. Basically turning the device on or of, enabling/disabling away mode, enabling/disabling boost mode, and enabling/disabling overpressure mode. These are features that also exist on the gen3 remote from toggle buttons.
I think, the actual fan speed can be controlled by the 4x00001 register. with that register, you can set the fan speed from 0 = off, 1= min, 2 = standard, 3 = medium and 4 = max. Even though the documentation implies that it’s only for the AC fans, I think it also to control the EC fans.
There is also the 4x00026 register which allows you to set the fan speed for the boost mode.
All of these options are actually also available from the gen3 remote. This does makes sense because the remote is using the same registers to communicate to the unit as well so in theory, everything the remote is able to to you should be able to do with modbus as well.
Maybe I could clone the repo and help you out a bit? It would be cool if the app could have one extra tab with a couple of toggle buttons for on/off mode, boost mode, away mode and overpressure mode. And redesign fan speed the select tab to actual control the fan speed. And also add the accompanying flow cards of course.
The above proposal would also make the app a lot simpler. I see you made a method to send multiple coils at once in order to toggle certain modes on or off depending on which ‘fan speed’ you select. That would no longer be needed anymore as each toggle or select would only send one command.
I don’t have much time to work on the apps right now, so if you are able to do the changes and do a local install on your Homey to see if this solves it for you, that would be great. Then it could be added to the public app later if it works as expected
Hi, my modbus device have A B + - Shall I connect the 0 to - ? Or shall I just not connect 0 at all? The power to the modbus device is on the +/- pins… so the - will have 2 connections, power and modbus…
I have A,B, GND (-) and VCC (+) on my device. I have A,B and GND connected, so try to connect the - if you haven’t and it’s not working already.
Okidoki, I will give it a try, hope it will not break… then this modbus to wifi device can be on the ok hardware list
That works like a charm
I have the wifi to Modbus device Elfin-EW11A to a Östberg HERU 100 S EC and all the data looks perfect!
Connections is “A”->“A” “B”->“B” and “0”->“-” the power for the Elfin-EW11A is using the “-” and “+” so the “-” is used 2 times.
Time to try out some flows
Hi, would it be possible to have more advanced energy consumption reporting? E.g specify max watt for the fans and heating coil in advanced settings, and use extract/supply fan power and heating power to calculate consumption
The problem with this is that heat coil isn’t always active when it’s turned on in the system, and it’s not reporting when it’s active, so it would be a guesstimate which in many cases would be conpletely wrong. The best way to have energy reporting would be to put a smart socket where the unit is powered.
Edit: I see that there actually is some reporting of “Current heat power” and “Current heat/recovery power” 0-255 (0-100%), but it would still be a lot of guessing to combine this with fan speed etc, so I still think it’s better to just monitor the supply to the unit for accurate power consumption.
Thanks for checking it out. The effect on a Heru 200 s is above whats recommended for a smart socket (coil 2300w and fans 320w), so I was hoping for a easy solution without having to call an electrician
Software should never be a fix for a bad or potentially dangerous hardware connection!
You should never connect a device that exceeds the max rated load of a smart switch and then rely on software to limit the load. This is very dangerous! Measuring power usage is a nice gimmick that could give you more insight into your power consumption, but it should never come at a cost of safety.
Also, in Europe, devices that have a maximum rated load of over 2kW, should be connected directly to a dedicated circuit with a sufficient circuit breaker and RCD (Residual Current Device).
Deep breaths, buddy I think you got things mixed up. I am well aware of the limitations in a smart socket. I was mere hoping that the app could estimate the power consumption based on fan rpm and heating coil power. The smart socket has never been an option, so I’ll probably get an electrician to install something like a Shelly plus 1pm.
How do you get 0% for Extraction in OVERPRESSURE mode? (I have 41% Supply + 42% Extract)
(I need to be able to adjust the Supply/Exhaust ratio to e.g. 60% Supply + 10% Exhaust, due to seperate kitchen extraction hood…)
You can adjust the speeds in the different modes in the service menu of the unit (not available through Homey app). See the first post on how to access the service menu
In the Service Menu of the unit, I can only adjust the Extract fan speed for the 3 modes Minimum + Medium + Maximum. The Supply fan speed is for all 3 modes, is automatic adjusted according to the Supply/Extract ratio that is set in the ‘Standard (%)’, when I change the Extract fan speed.
In the Service Menu, the only thing I can adjust for Overpressure, is the Duration.
What I want, is to change the Supply/Extract ratio for the Overpressure mode, so when our extraction hood in the kitchen is running (or when we use the fire stove in the living room), the HERU blows significant more air in the house, than it extracts, creating the right pressure balance for the extraction hood to work
Looking in the manual of my unit it does not seem like it’s possible to do what you want I would suggest to contact Östberg to see if they have a way around it.
FYI: I’ve started looking into this. I will do some testing and compare the results towards the actual consumption measured with a smart plug. If the values are close-ish to the actual consumption I will add support for it to the app
Update:
I used a Frient Smart Plug Mini to compare actual against the calculated with the following result.
Mode tested | Approx | Reading |
---|---|---|
Startup (exhaust fan @ 54%, Supply fan @ 0%) - No heating | 54.81 | 40 |
Normal (exhaust fan @ 54%, Supply fan @ 56%) - No heating | 111.65 | 61 |
Boost (exhaust fan @ 100%, Supply fan @ 100%) - No heating | 203 | 218 |
Overpressure (exhaust fan @ 20%, Supply fan @ 56%) - No heating | 77.14 | 46 |
Normal (exhaust fan @ 54%, Supply fan @ 56%) - Heating element (100%) | 1311.65 | 1410 |
As you can see there are some differences between measured and calculated values. Of course I cannot say how accurate the smart plug readings are either.
So then the question is if anyone thinks this is something that’s useful to have in the app, or if I should just scrap it since it’s just approximate values?