I know about GW PTC elements.  They also sell dual elements made for 230VAC and lower voltage DC.  In your case, you want to feed everything from 230VAC, so that sort of dual element wouldn't work.

Best to speak to GW in person.  If you are really lucky, they might even have the SPDT relays.  Or newer or older MAX or other model  PCBs might be fitted with the double-throw relays.  You might not be the first person with your requirement.

Yes, I'm also aware of the AC/DC PTC elements. That's not what I'm looking at. It seems like they are selling AC-only elements as well. Once my solar is set up and running, then I'll pay them a visit. 

3 hours ago, suds7162 said:

In a perfect world, I want to be able to use the geyser's original thermostat. Those devices are reliable, and they fail open, not closed. This seems like it's the one missing piece to the puzzle. I'm not comfortable wiring in another temperature sensor and using software to control things. My software is always written 100% fault free, but still.

Are your into ESP32 / Arduino stuff? 

If so, you can keep your existing thermostat as it is place.  Mount a low cost but accurate DS18B20 temperature sensor on the element flange nut with opoxy / thermal paste. You will be surprised at the dynamic range in temperature this will give you!! . There will be an offset from true water temperature at the vicinity of the element. but it is reasonably linear. 

So the idea is to set the main thermostat just outside the wanted max temperature you will be operating on. In this manner it will be your safety watchdog. Use a Sonko 40A relay (same as in geyserwise and cheap)  to control. In this manner you still comply because there are no mods to the COC stuff (element/thermostat) 

It will take a bit of logging and calibration to get to using the sensor values but its workable. 

Edited March 27, 20233 yr by BritishRacingGreen

Quote

Are your into ESP32 / Arduino stuff? 

I very much am into those things. I have a couple of ESP32s playing the part of an interface between some appliance and my HomeAssistant instance. 

But...

Hot water is mission critical stuff. I will be asking for a lot of trouble going down that route, only for it to stop working when I'm not there, and the water's cold, and my wife wants to take a bath, and and and. You know the story. 

I am actually planning on renting out the property in the near future. We are moving to another country. So then even more so, whatever installations and modifications I make must be such that it's repairable/serviceable by a plumber/electrician, because I will not be around to stand on a ladder with a laptop plugged into an ESP32 glued to the side of the geyser 😂

If my near future did not involve an emigration, then I would have rolled my own ESP32 based smart geyser controller and called it a day.

16 minutes ago, suds7162 said:

I very much am into those things. I have a couple of ESP32s playing the part of an interface between some appliance and my HomeAssistant instance. 

But...

Hot water is mission critical stuff. I will be asking for a lot of trouble going down that route, only for it to stop working when I'm not there, and the water's cold, and my wife wants to take a bath, and and and. You know the story. 

I am actually planning on renting out the property in the near future. We are moving to another country. So then even more so, whatever installations and modifications I make must be such that it's repairable/serviceable by a plumber/electrician, because I will not be around to stand on a ladder with a laptop plugged into an ESP32 glued to the side of the geyser 😂

If my near future did not involve an emigration, then I would have rolled my own ESP32 based smart geyser controller and called it a day.

Ok, then by all means, don't go that route.

if i can add my 2c. 

 

the Aux output can be programmed to always be on grid. when there is PV, it will push all the excess PV to the Aux (set the threshold to 0w). IF the grid falls away, and PV still available. it will still provide. set the Aux Load off battery setting to a high number (99%), otherwise it use your battery. 

from there you can set your geyserwise timer for lower temps at night, and higher temps during the day (i would just stick to a reasonable temp during the day) heat loss becomes stupid the higher the temps. and if you have so much extra PV. perhaps invest in another battery. 

 

my personal opinion, you need hot water. period. whether it is sunny, rainy, light or dark. 

so if there is no sun for the day. you still need hot water by 18:00 to go shower or bath. 

set the timer to do so. if there is PV, it will heat it. if there isnt, eskom will have to do it. if there is no PV or eskom. well. welcome to south africa. 

Since you mention you might rent out the property, dont over complicate it. 

 

using excess PV to heat the geyser beyond normal temp sounds great. use it for storage... having the same temp water every time i open the hot water tap is actually essential to me. (i have young kids that run their own bath)

 

what you might have to play around with, high or low Watt element. the timer will switch on. regardless. do you want to try and get the water hot as quick as possible, risking drawing some grid power if the PV is too low? or do you want a lower Watt element and have a constant draw the "whole day" and perhaps stay within the PV capabilities.

 

below i list more silly ideas:

-         geyser plate made with two AC elements, each with heir own thermostat

-         put your geyser on the Aux output, crank up the temp to 70deg and untick the "always on grid" so only PV will power it. you will have to raise the PV watts. and install a small push trough geyser after the main geyser. if the water is too cold, eskom will heat it. or a smaller size geyser with temps set to minimum acceptable temp. 

On 2023/03/24 at 12:12 PM, root said:

Subscribed. I'm also looking to manage my geyserwise system a bit better. 

I have a Victron setup that talks to my HA via MQTT. Grid state, Batt SOC and more is already being pulled in by HA and used as conditions. My entire house is on the essential side and like you I don't want the geysers to drain the batteries.

I would also like to manage geyser temp and load (power pulled by the geyser) intelligently. A easy way woud be to simply switch the geyser on and off via a sonoff pow or similar. But then I lose the circulation pump during those times. I would also like to bump up the geyser temp and use it for additional energy storage when the batteries are full.

I'm a DevOps/Systems engineer by day. So I don't want any cloud based control I don't have oversight over. So all my Sonoff bits have been reflashed with tasmota. Can the same be done with the Geyserwise Tuya?

https://mybroadband.co.za/forum/threads/geyserwise-tuya.1206468/post-30962577

Edited March 28, 20233 yr by mzezman

In case anyone is interested, I have my geyser hooked into my Home Assistant setup, switched using a Sonoff THR320 (flashed with ESPHome), with temperature read using a Geyserwise thermostat. The Sonoff is only able to read a digital 1-wire sensor, and the Geyserwise thermostat is an analogue thermistor, so I had to use an ATTiny85 to intermediate. My geyser is currently a 3kW, but I am planning to downgrade it to a 2kW to make it easier to actually run it from the inverter without drawing from the battery.

My THR320 has 3 profiles defined, "Home", set to 55C, which is enabled at power-on, as if it were a regular geyser, "Boost", set to 65C, and activated whenever there is sufficient excess solar, and "Eco", set to 45C, which is activated overnight. It is quite interesting to see how quickly the temperature drops from 65C, but how it can stick at around 45C for 12 hours with no external input!

Happy to provide more info if anyone is interested.

Oh, the other thing I saw that might be of interest to folks is a 3-phase geyser element. e.g. https://reliablestore.co.za/products/220v-3-6-9kw-dn40-hexagon-head-electric-heat-tube-solar-energy-water-tank-tubular-heater-element-2?variant=41866928652449&sfdr_ptcid=28846_617_685680567&sfdr_hash=0bdc59b81b69d4572d9f9218d2e92de1 

I haven't found any locally, but it seems that you may be able to get a 3kW element, which has 1kW on each phase. Of course, you don't HAVE to have 3-phase power, you can simply switch in additional elements if you have excess solar, or switch them out to reduce the load on your inverter.

Might be a better solution than jerry-rigging a plate with two elements in it.

Lategan & Van Biljon sells 3 phase elements: 6kW 3 Phase Industrial Boiler Hard Water Element without Pocket (lvb.co.za) I used one of these in my home brewery a while back. 

Problem is it does not come with a thermostat pocket, and you will still need to somehow independently switch the two AC sources.

First prize would be a mechanical dual thermostat, that's connected to the geyser, that's capable of switching two AC sources depending on differently set temperatures. 

Modifying thermostats, DIY solutions with Arduino or similar or whatever is something I'm just not really that keen on. Hot water is mission critical, and it should Just Work.

Having said that, I have been using my geyser connected to the Aux output of my inverter for almost a month now. So far I only had 2 semi cold showers 😂 during inclement weather. 

Something as simple as a change-over switch for the geyser, to take it over to Eskom in such cases is the cheapest and easiest solution.

 

 

On 2023/04/25 at 10:24 AM, suds7162 said:

Lategan & Van Biljon sells 3 phase elements: 6kW 3 Phase Industrial Boiler Hard Water Element without Pocket (lvb.co.za) I used one of these in my home brewery a while back. 

Problem is it does not come with a thermostat pocket, and you will still need to somehow independently switch the two AC sources.

First prize would be a mechanical dual thermostat, that's connected to the geyser, that's capable of switching two AC sources depending on differently set temperatures. 

Modifying thermostats, DIY solutions with Arduino or similar or whatever is something I'm just not really that keen on. Hot water is mission critical, and it should Just Work.

Having said that, I have been using my geyser connected to the Aux output of my inverter for almost a month now. So far I only had 2 semi cold showers 😂 during inclement weather. 

Something as simple as a change-over switch for the geyser, to take it over to Eskom in such cases is the cheapest and easiest solution.

 

 

@suds7162 I have followed this thread for sometime and you just said what I wanted to ask all along... a change over switch! Was just worried that with my simple thinking I was missing something. I have a spare old 5kw inverter that I was planning to have run my normal 200L electric geyser with a 3kw element on PV panels. The plan was to keep things as they are on the geyser by letting PV provide AC to heat the geyser during the day, switchover to Eskom after sunset and use the timer to top up the geyser as per normal or as deemed fit. The geyser wouldn't know who is giving power and won't care. My geyser currently on timer via Eskom is swiched on at 4am until 8am and again at 16h30 to 19h00. So was planning to let pv give AC to heat water during the day when sun shines, then only use Eskom at 4am as usual using a change over switch. Just add some panels to run the other inverter. Or am I over simplifying a complex matter? Really keen to go this route.

 

12 hours ago, Unity said:

@suds7162 I have followed this thread for sometime and you just said what I wanted to ask all along... a change over switch! Was just worried that with my simple thinking I was missing something. I have a spare old 5kw inverter that I was planning to have run my normal 200L electric geyser with a 3kw element on PV panels. The plan was to keep things as they are on the geyser by letting PV provide AC to heat the geyser during the day, switchover to Eskom after sunset and use the timer to top up the geyser as per normal or as deemed fit. The geyser wouldn't know who is giving power and won't care. My geyser currently on timer via Eskom is swiched on at 4am until 8am and again at 16h30 to 19h00. So was planning to let pv give AC to heat water during the day when sun shines, then only use Eskom at 4am as usual using a change over switch. Just add some panels to run the other inverter. Or am I over simplifying a complex matter? Really keen to go this route.

 

I don't see any reason why this plan might not work. Before I went full solar, I was considering getting one of these GeyserWise PV systems. But when I started costing things out I noticed that it's actually cheaper to get a small AC inverter and some panels and connect that directly to the geyser.

If you have a spare inverter lying around, then this approach is a no-brainer.

I think it gives you a lot more flexibility compared to connecting the geyser to your "main" inverter.

The only thing that you might "lose" is the ability to retask the geyser PV array to do something else if the geyser is fully heated. If you have a single PV-inverter system, you can then divert the PV array to charge the batteries or power your home load or whatever. For R10k worth of panels it's probably not so bad, though. And again, if you have a free inverter laying around, the math changes significantly.

Noted. Spending R10k now is worth it considering the Eskom bill I will be reducing. Won't be much in winter but I won't need to top up the geyser in summer due to the less heat loss. If it doesn't work, I can just connect the panels to my existing Luxpower system. Will monitor savings and update once done.

10 hours ago, suds7162 said:

The only thing that you might "lose" is the ability to retask the geyser PV array to do something else if the geyser is fully heated. If you have a single PV-inverter system, you can then divert the PV array to charge the batteries or power your home load or whatever.

Yeah. Seems to me that your home load would be your geyser inverter’s “non-essential load”, so any surplus could be contributed to the house inverter. Not quite as smart as running them in parallel, but probably not an option if they are different brands/capacities/whatever.

1 hour ago, RoganDawes said:

Yeah. Seems to me that your home load would be your geyser inverter’s “non-essential load”, so any surplus could be contributed to the house inverter. Not quite as smart as running them in parallel, but probably not an option if they are different brands/capacities/whatever.

Problem is, everyone connects their geyser as a non essential, it's actually the MOST essential load in the house. Without hot water you have serious trouble. I'm honestly only half joking here. 

Mine is connected as a non-essential at the moment, and I've had one too many cold showers already. I'm busy designing a geyserwise implementation so that a minimum temperature of 45C is deemed Essential (i.e. the geyser MUST be at least this temp, at all times), and a max temp of 65/75C is deemed as non-essential (i.e. whenever there is exces solar, we can boost to that temperature).

The Sunsynk aux port is not working out so nicely as I hoped for me.

9 minutes ago, suds7162 said:

Problem is, everyone connects their geyser as a non essential, it's actually the MOST essential load in the house. Without hot water you have serious trouble. I'm honestly only half joking here. 

Mine is connected as a non-essential at the moment, and I've had one too many cold showers already. I'm busy designing a geyserwise implementation so that a minimum temperature of 45C is deemed Essential (i.e. the geyser MUST be at least this temp, at all times), and a max temp of 65/75C is deemed as non-essential (i.e. whenever there is exces solar, we can boost to that temperature).

The Sunsynk aux port is not working out so nicely as I hoped for me.

I was thinking of moving my geyser to aux. Please elaborate about it not working out as nicely?

7 hours ago, ZaydS said:

I was thinking of moving my geyser to aux. Please elaborate about it not working out as nicely?

If you want smart control of your geyser, using HA or similar, then it might just as well be on the essential loads.

The aux load doesn’t really cater for nighttime use, unless you force it to stay on permanently, In which case it might just as well be on the essentials anyway.

2 hours ago, RoganDawes said:

If you want smart control of your geyser, using HA or similar, then it might just as well be on the essential loads.

The aux load doesn’t really cater for nighttime use, unless you force it to stay on permanently, In which case it might just as well be on the essentials anyway.

For me, I just want it on when there's excess PV during the day. So, could work for me. When grid is present at night, I'm happy to use it as my geyser is on a heat pump which is on a timer.

My main concern is that it uses the battery when there's no/insufficient PV.

Your thoughts?

53 minutes ago, ZaydS said:

For me, I just want it on when there's excess PV during the day. So, could work for me. When grid is present at night, I'm happy to use it as my geyser is on a heat pump which is on a timer.

My main concern is that it uses the battery when there's no/insufficient PV.

Your thoughts?

If you are ok to use the built in controls in the inverter (battery level, solar generation), then it should work for you.

8 hours ago, ZaydS said:

For me, I just want it on when there's excess PV during the day. So, could work for me. When grid is present at night, I'm happy to use it as my geyser is on a heat pump which is on a timer.

My main concern is that it uses the battery when there's no/insufficient PV.

Your thoughts?

This is why I'm keeping the existing geyser timer to limit power draw from the geyser when it's not ideal for me. I will allow it to use Eskom at my request.

Middag

Ek wil my geyser wise se screan, die probe by die collector en die sirkulasiepomp aan my inverter koppel.  

Die geyser self moet soos nou steeds sy krag van Escom kry.

is dit moontlik?

Arno

On 2023/05/12 at 5:02 PM, Hartswater said:

Middag

Ek wil my geyser wise se screan, die probe by die collector en die sirkulasiepomp aan my inverter koppel.  

Die geyser self moet soos nou steeds sy krag van Escom kry.

is dit moontlik?

Arno

I believe the geyserwise might complain if there is no temperature increase when it thinks there should be.

On 2023/08/08 at 9:07 PM, Thingwala said:

Hey @suds7162 we've just released the Geyserwala Connect, it is a WiFi enabled drop in replacement for the Geyserwise display PCB which offers local only integration over MQTT and JSON REST, there is also a Home Assistant plugin. It has been specifically designed with home automation in mind. It will also act as a stand alone WiFi connected device. One can optionally link it to the Thingwala console for internet remote control too, e.g: https://app.thingwala.com/geyserwala/demo

Along with being able to provide your own external setpoint and element demand, it is also possible to logically disable the element which is great to manage energy consumption based on grid presence/battery SoC. If you have a pumped solar the pump stays active so you don't lose out on daylight solar heating when the grid is down.

For more info: https://www.thingwala.com/geyserwala/connect/

Ordered one and looking forward to installing it next week. Was great chatting to the guys and they seem to know what they are doing and will even support rather old geyserwise units.

On 2023/08/11 at 5:20 PM, root said:

Ordered one and looking forward to installing it next week. Was great chatting to the guys and they seem to know what they are doing and will even support rather old geyserwise units.

Hi Root. How is this system working for you and did you integrate your system through the Aux port? 

On 2023/08/18 at 8:20 PM, Oelof said:

Hi Root. How is this system working for you and did you integrate your system through the Aux port? 

Aux port?

 

The geyserwala unit is a drop in replacement of the old geyserwise screen/interface. It even uses the original button placement and housing.

 

I'll do a complete write up on a separate thread at some point. 

 

Here is the short version. It is (insert expletive) fantastic. Just buy one. Less than a 1000 bucks currently. Takes 5min to fit with one Phillips/star screwdriver. 

 

The geyserwala is a completely standalone unit. You don't need HA or anything else for it to work. It does however integrate seamlessly with HA. The guys already wrote the integration you simply pull from GitHub. Copy, paste, restart. It also retains the manual functions. My wife can still go and press the red button to instantly turn on the geyser like I trained her to do.

 

My geyserwise is old. More than 13 years old. The guys from geyserwala confirmed beforehand that it will work with my geyserwise max v11 and it does.

 

I can now do everything I wanted to do in the start of this thread. In the seperate write-up or thread I'll go over some of the things I think can be improved on and what my experience with it has been so far. I'm very happy with the geyserwala unit.