Hi all,

I know they say no question is a stupid question, but here goes...

I have just had a Geyserwise MWS installed. As it is wifi, it can be controlled through the Smart Life / Tuya App.

I am struggling to set up the automations (set the timers) and the documentation doesn't help much.

I want the Geyser to switch to Eskom between 13:30 and 15:30 only if the temp is below 55 degrees. Then at 15:30 it must switch off AC and stay off regardless of geyser temp.

I then want to do the same between 18:00 and 20:00.

The geyser should then not use AC power at any other time regardless of the geyser temp.

So the documentation says set up a schedule to turn on AC Boost at 13:30 if the temp is less than 55. Then the next automation is if the geyser hits 55, switch off AC Boost. I did that and it works.

But the problem is at 03:00 this morning, the geyser switched on and started heating which I don't want (trying to save money here hehe).

So I suspect, somewhere I have made an error with the automations.

Any guru have experience with the Geyserwise MWS and Smart Life App?

Thanks all

So update:

I phoned Geyserwise and discovered that there is a factory default timer set which is why the geyser came on at 03:00.

Secondly they don't recommend using scenes in the Smart Life App. Rather just use schedule to power on and off.

Actually suggested only use the app for monitoring and Ac-Boost if needed. The controller timers take precedence over the app.

So I am now sorted. This is the first time I am using Geyserwise so definitely a learning curve

1 hour ago, Bucks_Fizz said:

This is the first time I am using Geyserwise so definitely a learning curve

Thanks for sharing. I have been thinking of replacing my CBI Astute controller with something else (it is not performing reliably, sometimes not switching on even though it sends a notification that it has...), and this Geyserwise looks as if it could work for me. Can you please elaborate a bit on the unit (is it just a controller or must one also buy a special element, cost, etc?). Also, does the controller have it's own battery backup power, or is it just powered from AC (as the Astute is...).

On 2025/06/14 at 9:54 AM, HennieL said:

Thanks for sharing. I have been thinking of replacing my CBI Astute controller with something else (it is not performing reliably, sometimes not switching on even though it sends a notification that it has...), and this Geyserwise looks as if it could work for me. Can you please elaborate a bit on the unit (is it just a controller or must one also buy a special element, cost, etc?). Also, does the controller have it's own battery backup power, or is it just powered from AC (as the Astute is...).

Morning,

As I said, I am new to this so may not be the best to give info hehe. However, what I did was a solar conversion. They used my existing Geyser & element (4kw Heath), added solar panels, control unit and LCD controller (MWS). So during the day, the sun powers the geyser. Then I set timers on the unit itself, to use Eskom (if needed) in the afternoon and evening. You can set temps on the unit so at say 18:00, I want it to heat the water to 60 degrees. If it gets to 60 before 20:00, the element switches off and will only come on again if the temp drops by 6 degrees. If it is outside the scheduled timers, doesn't come on at all. You can set up to 4 timers.

I know they can also replace the element to a 2KW element if you desire. Also part of the kit.

I am not sure if the control unit has a battery backup, some say yes, some say no.

I am having issues with the temp readings though. It drops by 20 degrees after two 5 minute showers. But the water is still scalding hot. So I have mailed Geyserwise to ask for advice

Good luck...

Thanks for your response, Bucks_Fizz - appreciated.

I'm not interested in anyone installing solar, as I have a system that is working very well... I'm "off-grid" for all practical purposes, even heating my geyser for an hour every morning between about 04:45 and 05:45 using my batteries. As stated previously, I'm just not very pleased with my current timer/controller that occasionally forget to switch on my geyser. No big deal, though.

I will contact Geyserwise for some prices, and do a Google search for more info. Again, thanks for your feedback, and good luck with the temperature dropping problem.

Anyone here tried to get this integrated into Home Assistant with the Tuya Local integration instead of the cloud.

On 2025/08/19 at 6:12 PM, WazzaCPT said:

Anyone here tried to get this integrated into Home Assistant with the Tuya Local integration instead of the cloud.

The only way I found to get Geyserwise into home assistant is using Tuya local the cloud wont even recognise geyserwise.

The local has better support, and more devices avoid the cloud if you can

one you click the Add device in the Tuya local integration it should pick up your geyserwise.

things to be aware of with this

1. To set a target temp you will have to set the 4 target temps unless you like the 4 6 hour block method that geyserwise ships with.

2. Because of no 1 above you will need to change multiple settings at once in your automations but the Tuya local gets confused when you do this so build in a delay after you change a setting before changing the next setting if you don't do this only some of the changes will not take effect

Edited August 29, 2025Aug 29 by regbes

On 2025/08/29 at 10:34 AM, regbes said:

The only way I found to get Geyserwise into home assistant is using Tuya local the cloud wont even recognise geyserwise.

The local has better support, and more devices avoid the cloud if you can

one you click the Add device in the Tuya local integration it should pick up your geyserwise.

things to be aware of with this

1. To set a target temp you will have to set the 4 target temps unless you like the 4 6 hour block method that geyserwise ships with.

2. Because of no 1 above you will need to change multiple settings at once in your automations but the Tuya local gets confused when you do this so build in a delay after you change a setting before changing the next setting if you don't do this only some of the changes will not take effect

Hey Regbes,

The regular Geyserwise works flawlesly though the Tuya Local, but the MWS was not having a great time. Tried to do a custom config file for it. I did submit it as a new device request on the GitHub page.

Kind Regards,

On 2025/06/14 at 8:38 AM, Bucks_Fizz said:

So update:

I phoned Geyserwise and discovered that there is a factory default timer set which is why the geyser came on at 03:00.

Secondly they don't recommend using scenes in the Smart Life App. Rather just use schedule to power on and off.

Actually suggested only use the app for monitoring and Ac-Boost if needed. The controller timers take precedence over the app.

So I am now sorted. This is the first time I am using Geyserwise so definitely a learning curve

Yoh,

This is frustrating. Kinda makes having the Wifi setup kinda pointless to some degee.

What I have learned over the last 72hrs is that the thermostat (That checks temp) is obviously close to the heating element. First morning automation it turned on at 6am...and 7min later turned off cause it hit the desired temp....but that was like localised temp, not the combined temp.

I then explored whether I could make an automation to:

IF 55Deg AND On
Delay 30min
IF 55Deg and On, Turn Off

Or something that checks the temp over a period, but you can only add 1 delay.

I then tried to create a scene, just for this check and delay...cause you can add scenes to a scene, but that in and of itself is flawed.

I dont know what the solution is. Do I get a thermometer linked to Wifi that can chill in the water on the oposite side of the geyser? Probably not.

I also have your issue with it randomnly going on at 3am. Very frustrating but I guess that is the blocks thing. In a perfect world (And this should be easily done with some coding), it should allow me to remove blocks, create my own schedule, block temps and so on. For now I have set Block 1 (Midnight to 6am) to 30deg, so it does not do anything stupid. As with anything in tech, there are solutions. but knowing how to fix something and it getting fixed are 2 different problems.

Im also wondering what the point in the schedule is, cause the blocks are there, but I guess I will learn.

How has the geyserwise mws been working out so far? Since you posted your question in June I'm hoping I can take from your experience so I can make a decision whether to acquire it or not. What savings have you seen? Im interested in getting it with 3 x 450W solar panels.

https://livestainable.co.za/products/geyserwise-megawatt-saver-mws-100l-to-200l-smart-solar-geyser-conversion-kitgeyserwise-megawatt-saver-mws-100l-to-200l-smart-solar-geyser-conversion-kit

https://www.voltex.co.za/product/canadian-solar-panel-mono-perc-455w-cs3w-455ms/88

Hello Peeps,

I have created a device config for the Geyserwise MWS units for the tuya-local integration of Home Assistant.

There are still some general bugs with the Geyserwise device itself.

This config has been tested briefly to get it operational at a site with two unit.

I would appreciate if some more users could test it out before I create a pull request to the main repository.

https://github.com/Waz-Cpt/tuya-local

If you want to just add the single file to the custom_components folder them you can download the file and upload it directly for testing.

https://github.com/Waz-Cpt/tuya-local/blob/55581ae9ef1992e677adb7287400f2f6a1ca437f/custom_components/tuya_local/devices/geyserwise_mws_water_heater.yaml

Once uploaded, restart HA and you can go through the process of adding a Tuya Device in the Tuya-Local integration. It will detect the device type for you and you will have a water_heater device and entity along with the corrected error messages and other settings.

Please DM me with feedback of questions. Or comment on this thread.

On 2025/11/05 at 10:05 PM, mlbd said:

How has the geyserwise mws been working out so far? Since you posted your question in June I'm hoping I can take from your experience so I can make a decision whether to acquire it or not. What savings have you seen? Im interested in getting it with 3 x 450W solar panels.

Well I'll answer some of this since I've been living with 2 of these for the last couple of months and the savings for me were astounding but mostly because of a poorly thought out solar installation that was installed by the previous owner, let me explain...

I have 3 phase power and use a lot of power for irrigation, water etc since we're off grid completely with water, previous owner was spending R5K per month for electricity and so were we when we first moved in. The main problem was that 6 of the 18 panels had major shading and would only start making any decent power from around midday so I added another 6 x 600w panels that get no shading which obviously made a massive difference.

I then used these shaded panels (didn't move them) for the geysers, 3 per geyser, they're older panels so peak power is low at around 800w combined and voltage hovers between 115v to 125v, these Geyserwise units apparently cut off at 115V but I think its lower as I'm still getting temperature increase when its at 115w. The smaller 200l geyser now uses no Eskom at all and gets up to 70 degrees every day if I let it, the bigger 250l needs about 1 hour Eskom to suplement and get it up to temp, I am probably going to add 1 more panel for the bigger geyser and recon I'll then use no Eskom for geysers until winter.

Before the change I'd run the 250l geyser which had a 1.2kw element for 8 hours everyday and the other 200l / 1.2kw element for around 3 hours ever day so its a considerable difference, I have changed these elements out for 3kw elements as their resistance is lower so needs a lower wattage to power the element.

Since this change I'm spending about R500 on electricity so its been significant and the system will quickly pay for itself, I changed out the inverter for a single 12kw Deye, had 3 x Luxpowertek's in before which were junk.

My only advise would be to rather spend an extra R200 per panel and go with 3 x 600w panels instead of 3 x 450w, they're pretty much the same size and it will make a huge difference to your performance and if budget allows 4 panels are even better.

Calcs below from Geyserwise for panels vs elements.

Specifications of Elements and Thermostats – Please see calculations for expected system performance

All fixed resistive elements and thermostats are rated for connection to standard AC power., which is 230V with a sinewave frequency 50Hz.

Connecting to a fixed AC resistive element without a MPPT will result in efficiency being compromised by ±40% in good conditions this can decline to as much as 60-70% in poor overcast conditions.

Geyserwise has specifically designed the Geyserwise MWS with MPPT to effectively operate at maximum power efficiency of 99 % in the voltage range of 120 VDC to 350 VDC.

Use the below formula to calculate the PV array to best match the performance of MWS with different size heating elements.

P=Uvmp x Uvmp /R

R = (12 -17 or 27 Ohm)

2 Kw = 2000 watts with a resistance of 27 Ohm

3 Kw = 3000 watts with a resistance of 17 Ohm

4 Kw = 4000 watts with a resistance of 12 Ohm

If a 550-watt panel array is used with specification below:

550 Watts

41.7 Vmp

13.20 Amp

49.6 Voc.

The panel maximum current must be below 15 Amp.

Use a minimum of 3 panels in series

UVmp = 3 x 41.7 = 125.1

UVmp x Uvmp = 125.1 x 125.1 = 15650

On a 2 Kw element 15650/27 = 579 watts at peak.

On a 3 Kw element 15650/17 = 920 watts at peak.

On a 4 Kw element 15650/12 = 1304 watts at peak

The lower the resistance the better the performance.

Results of connecting four panels in series:

On 2 Kw element 27822/27 = 1030 watts at peak

On 3 Kw element 27822/17 = 1636 watts at peak.

On 4 Kw element 27822/12 = 2318 watts at peak.

Edited November 11, 2025Nov 11 by Jatho