I have expanded my solar PV array and now wish to dynamically power storage heaters using the surplus power. As an elegant option I want to do this using Homeassistant and ideally control the heater directly via wireless rather than smart switches.
I have discovered the Elnur Ecombi SSH which use 868MHz but they require a G-control hub to do a minimum of connecting to wifi and then use an App to control the heaters which is a useless concept for me. Alternatively if you have the smart solar heaters you can then also buy their Solar Box all tieing in to their system and their control logic.
I already have an Elnur Ecombi SSH and I want to interface to the 868MHz radio and wonder if anyone has had any success with this? I think that the G-contol system may be similar to the same as the Haverland, Somfy, DSR systems but I donāt know.
The second option would be to get the g-control gateway and try to interface to that or just stick with what I have trialled so far with Tasmota smart switches controlled via MQTT for other āthickā heaters. I am not sure if the Ecombi is too clever to use in this way though.
Anyone have any experience of any Elnur direct control?
Hi,
I have just found this forum and am happy to have found someone who is working on a similar project.
To answer your question - no, I donāt have any experience of Elnur direct control.
But, I do have an Elnur Ecombi Plus and a G-control hub. We are off-grid solar and I use the heater to make use of excess energy once our batteries are fully charged. At the moment I use a ādumbā remote control (430MHz) which is switched by a relay output from the solar charge controller (Midnite Solar Classic). I have modified the heater by inserting a relay in the storage heater element circuit. Itās crude but it works - mostly! So, I am only using the G-control system to monitor the only heater that we have. It isnāt doing anything useful, really.
This was just an experiment to check the viability of storage heaters in our situation and now I am planning a big expansion to our PV arrays to give us a better heating system. I have an additional inverter and will be installing more Elnur heaters and an air-to-air heat pump. I need more flexibility of control and Home Assistant looks like the way to go. Ethernet switches should work more reliably than my āhackedā remote controller. I have a spare RPi and I think that I must start playing with the software. I am more a hardware builder than a software expert, but I think that there will be enough expertise on this forum to get me going. Plenty of people have been this way before me.
If we can bounce ideas off one another then it could be mutually helpful.
Hi John,
Thanks for your response, I am sure sharing information will help us both.
I have requested information from Elnur but nothing has been forthcoming so I am working with Plan āBā using Tasmota smart switches. I have found that to use MQTT these need to be using the latest version 11.0.0. I have some Teckin smart sockets which have upgraded without issue but the Slitinto ones I have have all bricked on trying to OTA upgrade.
When I installed my first PV array 8 years ago I installed an Openenergy monitor system and one of Robin Emleys PV Routers to dump to the immersion heater and then to an old storage heater driven by a Triac so is a variable load. This has been excellent.
This year I have had a second PV system approved to take the total up to 9.5Kw. This is why I started looking at the Elnur heaters. They may not actually have any advantage over other more dumb heaters but the styling and Ebay prices were attractive. I have ended up with an ECOSSH208, 308 and 408.
As smart sockets are probably only really rated at 10A despite what some specs say I am thinking of getting a 4 relay smart relay unit to fit inside the case of the 408, this would give the additional benefit of being able to individually switch the 4 elements to be a smoother load increment rather than switching 2.8Kw in one go.
The EMONCMS system provides the power monitoring to Home Assistant which I use. The second Fronius inverter I have can now also provide information via the integration. I use Mosquitto to communicate with the Tasmota devices.
I have just checked that both Zigbee and WIfi do actually penetrate through to inside the base of the heater as I thought it might be too much of a Faraday cage and need an external whip aerial which adds to the complexity as all the available boards seem to just use the PCB antenna with no socket.
Thanks for getting back to me. I have one ECO 158 Plus. Itās the smallest in the range but the heater element was a perfect match for the surplus energy from my PV system. The current āmainā system is 2.8kW and my plan is to make this up to 9.6kW later this year. I have 2 smaller PV systems which are my back-ups. Being off-grid, the inverter and charge controller hardware will be different to yours. I am planning on adding several new heaters - at least one ECO408 and another 158. I should be seeing a chap selling a batch of storage heaters, locally, but I donāt suppose that they will be Elnur models. As you say, these Elnur heaters look good in the house and have some attractive features, even though we are overriding them with our smart relays.
I have, this afternoon, loaded the Home Assistant system onto a Raspberry Pi and am now embarking on a steep learning curve! I like your idea of the 4-stage element switching for the 408. Iāll probably do that. Can I pick your brains, please? I need to get going with some smart devices. What would you recommend? For the heaters, it would be a hard-wired remote relay function. Is a Sonoff R2 suitable? I also need a way to detect the state of a relay contact to use as an input to the smart assistant system. (Sorry, I am not up to speed with the correct terminology.) Can I use a Sonoff R2 for that function? What plug-in units are recommended?
Having read these questions I can see that I look like the ānewbieā that I really am! I should really just go and read the f****** manual shouldnāt I?
As an aside, do you have any amateur radio connections?
Hi John,
Regarding smart devices:
I recommend using those that can be used with Tasmota as I am a great believer in Open Source and it works well with Home Assistant, no requirement for permanent Internet connection and no external servers meddling with your services. That said probably anything that uses MQTT will work and there are probably other methods too that others would recommend.
That said it does seem to be a bit of a mine field as to which can be re-programmed via OTA. The Tasmota site gives guidance but itās not a dead cert that it is going to work. I bought a few teckin devices a few years ago but then the word was they had since made them secure. I bought some Slitinto devices which worked initially but when I tried to upgrade to a later version of Tasmota they bricked and accessing for serial download is proving difficult.
There does seem to be a move towards making more devices available with a DIY mode which is perfect for Tasmota and seems to work well with OTA download.
I buy from Aliexpress and Banggood and there are some Athom devices that are pre-programmed with Tasmota which takes away the pot luck of wheher it might work. This is a current link:
Tasmota will allow you to monitor most states and data including the power delivered to the device over different timescales assuming the hardware supports it.
If Home Assistant does what you want it is easy to use but if you need to delve into YAML itās a lot more scary. For doing most of this I havenāt touched YAML at all so itās good and the automation scripting part is easy itās the initial setup of the monitoring I found more challenging but searching the Web ususally gives a clue.
For the 4 way relay I am looking at
but the size of the board is too wide to fit in the base of the heater, it will need to go in the side which then leads to reduced WiFi signal strength due to shielding so looks like an obstacle.
My system is currently sadly lacking batteries as they are on back order but once they arrive I am not sure what the dynamics of my system will be. There will be less power for the heaters but i need to be wary of drawing power from the batteries to feed the heaters if I get the monitoring wrong.
WRT amateur radio, no I donāt . I am a retired embedded software engineer who began as a hardware engineer with Green credentials too hence my attraction to this topic.
Sorry for the delay. Weāve had a couple of days away from the computer.
Thanks for the links. Having installed Home Assistant I really need to play with some smart devices. Iāve referred to the glossary so that I can learn what the words mean in context. Then I wonāt sound so ignorant. Iāll buy some of the modules you suggest and look out for a sensor device that will allow me to monitor the state of a relay contact. That will fulfil my basic requirements. I have seen that the possibilities are almost endless for applying a lot of intelligence. One interesting feature would be to include weather forecast into the control of the heaters. Because the fundamental source of energy in our house is the batteries (we have no mains), the state of charge of the batteries is top priority. I only take energy for heating (each day) once the batteries are charged because our dumb control system doesnāt know if tomorrow will be sunny. Having a forecast would give me a lot of flexibility. However, that is getting a bit ahead of myself! First things first.
We use lead-acid batteries for storage. They are āold tech.ā but reasoanably cheap and fairly reliable. Our main 48v battery has a capacity of about 37kWh. Itās big and heavy and needs weekly maintenance but a lithium battery of the same capacity would be rather pricey at the moment.
On my Elnur heater, I have mounted the remote control receiver in an ABS box which is outside the heater and connected by a white cable. If the box is made from good quality materials it can look quite neat and overcome the RF shielding problem. I used one from RS components.
Thanks for all the hints. Iāll place some orders and let you know how I get on. At this time of year, I have time to experiment before we need the heating again.
Hi John,
If you are getting into reprogramming smart relays you will at some point need to program ESP32 or ESP8266 serially for which youāll need a CH340G such as this, preferably with a prog switch:-
along with Dupont Jumper Cable / breadboard wires.
Elnur Gabarron have told me that their 868MHz protocol is secure so Iāll be leaving my tests with a LoRa LLCC68 test board for a rainy day sometimeā¦
How much sun do you get in your part of Spain and how much do you need heating?
For me my 3.5KW system gave around 3500KW hours per year so I am assuming I shall now be getting around 9500KW hours per year.
Of this I have, for this May with no batteries, used 90% ( I had a smart meter installed a month ago which means I now get to know my export). I suppose that for you with off-grid that itās not so easy to know if you havenāt used all the capability?
Thanks for putting me on the right path. Itās much appreciated. I understand about the response from Elnur Gabarron. Itās disappointing but not unexpected.
Our house is inland and at about 700m above sea level. We have plenty of sun, but we also have rain and snow. Sometimes we can have deep snow (well, more than wellie depth) and it will hang around for a week or two. So, we usually light our woodburner in October and keep it alight until sometime in March or April. Perhaps we are āsoftā! I donāt expect the storage heaters to meet all our heating needs but I hope that they will delay the need to light the woodburner and reduce the amount of wood that we burn.
Our charge controllers have very good data logging and I have been recording our solar generation for about 18 months as justification of the project. I just picked a random 365 days and found that our 2.8kW array produced 3,600kWh. I donāt have any logging of energy consumption. It would be interesting to monitor that, as well. Itās possible that we have the potential to produce more energy but the charge controllers shut down when the batteries are full, as you suggest.
Your self-consumption of 90% is really impressive.
Itās been a while but I am now getting somewhere. I had a problem with an inappropriate SD card in my RPi which set me back. To cut to the chase, I now have all the parts that you recommended and I have demonstrated that the system will perform the first basic function that I need. I can āenableā the heater element of the Elnur in response to a contact closure in our solar charge controller. The relay contact is porogrammed to close when our storage batteries a close to being fully charged.
I used the Athom Tasmota relay and a Shelly UNI as the āsensorā. Thereās still a great deal to learn, of course, and a lot more intelligence to build into the system. What I have achieved so far, with my ālash-upā, I could have done with a (very) long cable!
Do you have any experience with power/energy monitoring? I can see that it would be useful to monitor the power being supplied by my two inverters, as well as the daily energy consumption.
Iāll now proceeed with making my lash-up tidy enough to install.
Yes, I have for the last 8 years used the OpenEnergyMonitor products ; EmonTX and EmonCMS for my monitoring which can feed into HomeAssistant too and I am doing that but I now need information that I canāt get from that. I am now using the Fronius Solar API for obtaining battery state information in addition to all the other information mostly duplicated by the EmonCMS except that my first PV system is only monitored by the EmonCMS as I didnāt see the point in shelling out for a Datamanager option for this.
I did look at using Modbus as I was thinking of controlling the charge and discharge times of the battery but it was more complex and I can do the monitoring with the SolarAPI so Iām happy with that for now.
There is a Fronius integration for HomeAssistant in the form of the SolarNet Inverter which I believe to be applicable to other manufactuers too. Also the Sunspec seems to be an industry standard for Modbus that a number of manufacturers support so donāt just assume you are looking for a specific manufacturers integration, look for the wider standard that your inverter supports.
Thanks, Roger, thatās useful information. Being off-grid, my hardware is different. I am also operating a number of inverters from different manufacturers and of differing āsmartnessā. I have, however, standardised on a particular charge controller from Midnite Solar and I know that it uses Modbus. I have 5 of them so a bit of investigation will pay dividends, Iām sure.
Not directly using the 868MHz RF no. I am very happy with the use of Tasmota on the relay boards that I fitted in the lower right corner of the heaters with an external wifi antenna hacked onto the board. I have an ECOSSH208, a 308 and a 408. For the 208 I just used a regular Tasmota socket switching the power to the two elements together with no modification to the unit. For the 308 and 408 I have a relay swiching each of the elements independently and then wrote automation scripts to drive MQTT to switch according to grid export. I never bothered with changing the 208 as it is safely within the capabilities of the relay, the 408 is most definitely best hard wired anyway with no plug just fused and switched.
I only have the heaters and no hub. I had hoped go be able to use the 868MHz interface without the hub but it appears this is a proprietary protocol. So you might be able to interface to the wifi side of this but I didnāt want to spend the extra when the system probably wouldnāt work well for me with 2 foot thick walls.
I came upon this page while looking for options to increase my solar storage options for winter, so I thought Iād add my 2c! Iām located in NSW, Australia and while our winters are mild there are 3-4 months of cooler weather which require heating. My electrical situation is solar (currently 8.3kw Fronius) + battery (1 x Tesla PW). Everything in the house is now electric except for the wood burner but this is used on the coldest of days/special treat!
Iām thinking of installing a small Elnur storage heater but probably just controlling it via a simple wifi on/off switch (Shelly is my preferred device) and then using an automation to decide when to switch on/off.
IE: Is it winter/cold tomorrow?Is the battery full?Is the solar export>heater power?Turn on heater.
Alternatively Iāll use Node-red for the automation.
Iāve looked at the hub but the price seems very high (>130ukpounds or nearly $400 in au) for just one heater and I wish manufacturers wouldnāt use these proprietary devices. Just use Wifi and preferably a protocol which is compatable.
Anyway, Iāll link here a pdf of the G control hub installation I found
Is the battery full?