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I'm on solar now for 6 months, but geyser (200lt, 3kw) is still on Eskom. I want to go completely off grid. Which is the best geyser alternative? Solar, high pressure/low pressure, retrofit or gas? Considering purchase price etc.

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Hi, I have two  Geyserwise PV system. Its a kit that  consists of solar panals, a controller that supplies direct current from the PV to the element in the geyser and heats the water. I have a 200l and 150l geyser. They work very well in the sun, as do the systems that use the evacuation tubes (the common other well known method), but if after 5pm you use the hot water, the sun is gone, and you need to re-heat it somehow, or or wait for the sun again. I saw yesterday someone had two in parallel,  Once the first was cold he used the 2nd to supply the 1st. So in my view, how to do supply energy at night or when the water is cold, lets say due to rain like today?  My thoughts, if you dont use Eskom, then gas. Or just go gas in the first place because all the other systems need some form of electricity. Using a inverter would mean using your batteries at night to heat the water again, thats not cost effective.

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57 minutes ago, Petrie said:

I'm on solar now for 6 months, but geyser (200lt, 3kw) is still on Eskom. I want to go completely off grid. Which is the best geyser alternative? Solar, high pressure/low pressure, retrofit or gas? Considering purchase price etc.

Hi there. 
 

Retrofit 20 Evac tubes with a Geyserwise to the 200l geyser and change the element to a 2kw so you can run it off your inverter if needs be. Then get a Paloma 26 or Rinnai gas geyser and connect that in series after the solar geyser. Set the gas geyser to 45 degrees so that it will only heat the water to that temp. If the geyserwise shows that the water in the tank is above 45 then turn off the gas geyser. If below 45 then turn the gas geyser on to boost the temp to 45. You can also try 48 in winter. 
 

I ran that system in my previous home and used only 18kwh per month from the Grid and a 48kg gas tank lasted 13 months with 3 adults in the home. 

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I would say that it depends on what size solar system you have and whether you have any room for expansion or if you have available capacity. 
 

personally, I advise against evacuated tubes if you have solar already. I installed mine last year before I did my solar inverter install. I installed a 200l thermosyphon system that feeds into the existing 150l geyser which is on a geyserwise. On clear summer days, the system works great where the water easily gets to 80-90-100 degrees. But my solar PV also works great in summer.  However, in winter and on a day like today in Gauteng, the water temperature in the 200l tank only managed to increase from 29 degrees to 43 degrees. 
So 14 degrees change to a 200l (working on best case as water stratifies in the tank) requires around 3.2kwh. 
 

If I were to do it again, I’d just add the extra storage tank with a 2kw element and heat it to the max dom solar during the day. I’ve modified my thermostat and I heat the water to 80 degrees. 
 

With the evacuated tubes, if you don’t use it for a few days in summer, you have the risk of over heating and having water released through the pressure valve... also the circulation pumps failing.... etc. 

i like @Leshen idea of the gas geyser as a backup. My neighbor has been without power since yesterday morning. His meter burnt out and he’s struggling to get through to eskom. I’ve run an extension from my house to his to power his essentials. He has a flat plate collector but also has a gas geyser as a backup so at least he has hot water in this really cold weather. 

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@Vassenincrease from 29 degrees to 43 degrees >>>> Interesting, My PV system performed slightly better. From around 26 at 8 am after everyone that leaves home early had a shower to 45 degrees when I looked at around 4pm as the next "load" of showers happens before 7pm . Advantages of PV. No worries on any pipes external, No worries on outside components damage of EV or Flat Plate or leaks causing water wastage (the anti freeze stuff), no circulating pump. No complex install of on the roof to geyser or modify your plumbing to fit the EV system bla bla bla ,,, Disadvantage. EV get much hotter in summer and I have heard slightly more efficient in bringing up the temperature (If you want it to). I never go higher than 55C. Have replaced too many geysers in my lifetime to add to them breaking quicker. High High Tempreture like the 70 > 80 > XXX cannot be a good thing. Its not just they break and its replace (This is a pull out of roof could be anywhere. High high up on those complex and double story), there is always other damage. I look after mine. Change the anode regularly (R120) when I last bought and 10 minutes to do. Lower Temp, change anode > 10 years on a geyser.  I would have loved to plan for gas to be totally off eskom for hot water.

 

I’ve run an extension from my house to his to power his essentials >>>> , Can I be family? I help my neighbors with borehole water (100m deep is really good pure water) if they need Most have pools and use that water.

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9 hours ago, Vassen said:

I would say that it depends on what size solar system you have and whether you have any room for expansion or if you have available capacity. 
 

personally, I advise against evacuated tubes if you have solar already. I installed mine last year before I did my solar inverter install. I installed a 200l thermosyphon system that feeds into the existing 150l geyser which is on a geyserwise. On clear summer days, the system works great where the water easily gets to 80-90-100 degrees. But my solar PV also works great in summer.  However, in winter and on a day like today in Gauteng, the water temperature in the 200l tank only managed to increase from 29 degrees to 43 degrees. 
So 14 degrees change to a 200l (working on best case as water stratifies in the tank) requires around 3.2kwh. 
 

If I were to do it again, I’d just add the extra storage tank with a 2kw element and heat it to the max dom solar during the day. I’ve modified my thermostat and I heat the water to 80 degrees. 
 

With the evacuated tubes, if you don’t use it for a few days in summer, you have the risk of over heating and having water released through the pressure valve... also the circulation pumps failing.... etc. 

i like @Leshen idea of the gas geyser as a backup. My neighbor has been without power since yesterday morning. His meter burnt out and he’s struggling to get through to eskom. I’ve run an extension from my house to his to power his essentials. He has a flat plate collector but also has a gas geyser as a backup so at least he has hot water in this really cold weather. 

Yah back then I had a 300l Suntank close coupled geyser with flat panel collectors. Not very effective. 
 

Solar system : Goodwe 4.6ES and 17 x 330 Canadian Solar and 3 x US2000. 
 

Didn’t do too bad. Elec bill was around R300pm and gas lasted 13 months. At my new home, I have 2 x 200l (2kw element) elec geysers powered by the Sunsynk via Sonoff. Working well so far. Elec bill around R600pm. 

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3 hours ago, RyanG said:

@Vassenincrease from 29 degrees to 43 degrees >>>> Interesting, My PV system performed slightly better. From around 26 at 8 am after everyone that leaves home early had a shower to 45 degrees when I looked at around 4pm as the next "load" of showers happens before 7pm . Advantages of PV. No worries on any pipes external, No worries on outside components damage of EV or Flat Plate or leaks causing water wastage (the anti freeze stuff), no circulating pump. No complex install of on the roof to geyser or modify your plumbing to fit the EV system bla bla bla ,,, Disadvantage. EV get much hotter in summer and I have heard slightly more efficient in bringing up the temperature (If you want it to). I never go higher than 55C. Have replaced too many geysers in my lifetime to add to them breaking quicker. High High Tempreture like the 70 > 80 > XXX cannot be a good thing. Its not just they break and its replace (This is a pull out of roof could be anywhere. High high up on those complex and double story), there is always other damage. I look after mine. Change the anode regularly (R120) when I last bought and 10 minutes to do. Lower Temp, change anode > 10 years on a geyser.  I would have loved to plan for gas to be totally off eskom for hot water.

 

I’ve run an extension from my house to his to power his essentials >>>> , Can I be family? I help my neighbors with borehole water (100m deep is really good pure water) if they need Most have pools and use that water.

Mines on a flat roof that I’ve converted to a rose garden so it’s not difficult at all to get to. Shading also causes some issues for me. But being outside, That’s also why I don’t mind turning the temperature up as the leaks don’t cause any surrounding damage. 
 

if one doesn’t have solar PV then the evacuated tubes or flat panels makes sense as you have no other option. If you do have PV already, take the same money that you would spend on tubes and get another storage tank and heat it with solar during the day. 

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was hoping to read comments on heat pumps here. Seems they are not that popular . I have been reading that for a 200l geyser that uses 3KW heating element, you need a heat pump that uses only 1Kw. So 1kw of heat pump heats water the same way a 3kw heating element of 200L geyser heats up the water. Not sure how true that is and was looking to hear from the guys with heat pumps. If that is the case, then its much better to get a heat pump. 

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1 hour ago, Vassen said:

 

if one doesn’t have solar PV then the evacuated tubes or flat panels makes sense as you have no other option. If you do have PV already, take the same money that you would spend on tubes and get another storage tank and heat it with solar during the day. 

Totally agree. That’s why instead of 2 x 200l solar geysers which would have cost around R50K. I bought Heattech geysers which cost R11K and I used the rest towards my PV system. 

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2 hours ago, hoohloc said:

was hoping to read comments on heat pumps here. Seems they are not that popular . I have been reading that for a 200l geyser that uses 3KW heating element, you need a heat pump that uses only 1Kw. So 1kw of heat pump heats water the same way a 3kw heating element of 200L geyser heats up the water. Not sure how true that is and was looking to hear from the guys with heat pumps. If that is the case, then its much better to get a heat pump. 

My 200l heat pump uses around 900 - 1000 W, but it's spread over around 3 hours each day. It also has a 2kW backup element, but I hardly ever use it. Heat pump's utilisation is lower, but for longer, so it's easier on a smaller inverter. The problem is that it is electro-mechanical, with moving parts, so more maintenance-intensive, and relatively expensive to replace (about 25-30K over 5-10 years' lifespan).  

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 Gas geysers can be gas hungry if not installed correctly. 

Install a Gas Geyser in Parallel with your existing geyser, install ball valves so that you can direct the water flow. Use the gas when there is not enough sun.

Run the electrical geyser on your inverter from 10Am to 3 PM. replace the element with a 2kw element. Use a geyserwize to control the temperature as well as the switch over to mains. Switch the geyser off from 8pm. if you need hot water after 8 boil the kettle. 

Teach you family to shower early in the afternoon and not in the morning.

 

As A joke Tell them each person gets 10minutes in the bathroom. if we could get ourselves wet soaped and rinsed in 2 minutes surely the ladies can learn how to shave without water HE HE. 

 

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18 minutes ago, Krokkedil said:

 Gas geysers can be gas hungry if not installed correctly. 

Install a Gas Geyser in Parallel with your existing geyser, install ball valves so that you can direct the water flow. Use the gas when there is not enough sun.

Run the electrical geyser on your inverter from 10Am to 3 PM. replace the element with a 2kw element. Use a geyserwize to control the temperature as well as the switch over to mains. Switch the geyser off from 8pm. if you need hot water after 8 boil the kettle. 

Teach you family to shower early in the afternoon and not in the morning.

 

As A joke Tell them each person gets 10minutes in the bathroom. if we could get ourselves wet soaped and rinsed in 2 minutes surely the ladies can learn how to shave without water HE HE. 

 

A gas geyser like a Paloma or Rinnai is only gas hungry (5kg per hour) if it heats water from cold to 65deg. However they do come with controllers where you can select the temperature. If set at 48 deg and if the inlet water temp was say 40deg then the temp differential is 8 and the gas geyser would variably throttle the burners so that gas consumption would be way less. 
 

As said, with 3 adults in the home, a 48kg gas tank lasted 13 months. 

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2 hours ago, YellowTapemeasure said:

My 200l heat pump uses around 900 - 1000 W, but it's spread over around 3 hours each day. It also has a 2kW backup element, but I hardly ever use it. Heat pump's utilisation is lower, but for longer, so it's easier on a smaller inverter. The problem is that it is electro-mechanical, with moving parts, so more maintenance-intensive, and relatively expensive to replace (about 25-30K over 5-10 years' lifespan).  

Best geyser replacement is this one, https://cdn.shopify.com/s/files/1/1284/8335/files/EMS_Heat_Pump_Leaflet_Price_web.pdf?v=1618480219 . Heat pump with a tank of its own

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5 hours ago, hoohloc said:

was hoping to read comments on heat pumps here. Seems they are not that popular . I have been reading that for a 200l geyser that uses 3KW heating element, you need a heat pump that uses only 1Kw. So 1kw of heat pump heats water the same way a 3kw heating element of 200L geyser heats up the water. Not sure how true that is and was looking to hear from the guys with heat pumps. If that is the case, then its much better to get a heat pump. 

I was going to add my 2 cents but the question was about solar geyser to sort of go off grid. 
 

Here’s my 2 cents. I have a 200l daikin hot water tank where the heating element is sort of mid way up on the vertical tank and is meant to act as a booster to kill the bacteria in the water at regular intervals. It’s got a heat exchanger that is meant to be used to heat the water through a solar collector. Was initially going to install an evacuated tube on this but after the excessive summer hot water and the fact that this tank was in my ceiling, and was very inconvenient to go up on the roof if I needed to cover the tubes and the fact that my roof is west facing, I opted for a 5kw heatpump instead. Got an alliance pump which looks identical to the heat tech pump. Was a bit of a mission to get someone to sell me one as most places only allow it to be installed by there approved installers even after telling them I don’t care about the warranty. 
 

it works pretty well in summer, in winter it takes a lot longer to heat the water. Have mine set to 53 degree and it only works. Has 3 timers, so I top up the temperature at 5am, then it comes on at 10am again. And again at 8pm. So I use it when there’s no sun. The tank heating element comes on at 11 and goes off at 2pm I think. 
 

It’s expensive. With me installing it myself, it costed around 15k. I paid 10500 for the pump itself and you’d need a diverter valve that basically heats the water in the heatpump continuously until it gets hot enough to send to the geyser for storage. Without this, you would basically just be circulating the water in your geyser continuously and if someone were to take a shower at the time, you end up hot and cold water me alternating.  The heat pump can only heat water by a few degrees every time water flows through it so it’s a long process.
 

They also need to be serviced yearly if you get it installed by an approved installer.... which basically means an additional R1000 or so just for them to flush the system and clean it up a bit. I opted to not care about this as it seems simple enough. I do the same thing every six months or so. 
 

It’s efficient yes, but it also costs a lot and is not as simple as a electric heater element that can be powered by solar panels. So I try to limit the time that it needs to be used. 

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38 minutes ago, hoohloc said:

Best geyser replacement is this one, https://cdn.shopify.com/s/files/1/1284/8335/files/EMS_Heat_Pump_Leaflet_Price_web.pdf?v=1618480219 . Heat pump with a tank of its own

Why is that the best. It’s 29k inc vat before installation with an unknown lifespan. Also if the Heatpump breaks, you are stuck with a fancy looking geyser. With these all in one type systems, you are also stuck in terms of after sales support where you have to go via manufacturer Channels and who knows how much things cost then. 

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7 minutes ago, Vassen said:

Why is that the best. It’s 29k inc vat before installation with an unknown lifespan. Also if the Heatpump breaks, you are stuck with a fancy looking geyser. With these all in one type systems, you are also stuck in terms of after sales support where you have to go via manufacturer Channels and who knows how much things cost then. 

I say its best because it only uses 765W to give you the same heating as normal 3KW 200l geyser. If one already has a solar system, you can have this on day and night and have hot water 24/7. You do not need to worry about cloudy weather or gas consumption, you do not need to worry about putting up timers to switch ON and OFF. You also have an advantage of a 2kw heating element that you can use incase the heat pump breaks or for whatever reason. As for the aftersales support, how do you know that you will not get support for this unit when the guys who make it are in JHB. EMS is there in JHB and you can contact them for support.  IMHO, this is the best if you are replacing a complete geyser. It is not cheap though 😁

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Posted (edited)
19 minutes ago, Vassen said:

Why is that the best. It’s 29k inc vat before installation with an unknown lifespan. Also if the Heatpump breaks, you are stuck with a fancy looking geyser. With these all in one type systems, you are also stuck in terms of after sales support where you have to go via manufacturer Channels and who knows how much things cost then. 

I think that it's quite innovative, fiberglass tank (low pressure), very efficient way of doing heat transfer, and because it's integrated there aren't long pipes to yet another geyser, and all the associated limescale issues. Locally manufactured and supported with a Japanese (not Chinese) compressor. Agreed that it's pricey, but I will probably be looking to replace my own heat pump with it when it breaks down (it's 6 years old already). 

Check out the explanation video:

 

Edited by YellowTapemeasure
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44 minutes ago, hoohloc said:

He is looking for either high pressure or low pressure unit 

A Heattech 200l High Pressure geyser is R5500. A ITS 5kw Heatpump is R15500. Still cheaper than the ACDC product. Not that I’m a fan of heat pumps anyway. 
 

If you want to reduce your “overall energy” bill, you have to use the Sun in whichever way or form. 

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Posted (edited)
13 minutes ago, Leshen said:

A Heattech 200l High Pressure geyser is R5500. A ITS 5kw Heatpump is R15500. Still cheaper than the ACDC product. Not that I’m a fan of heat pumps anyway. 
 

If you want to reduce your “overall energy” bill, you have to use the Sun in whichever way or form. 

True, that's also an option. How good is the Heattech geyser warranty though, and how well does it perform at the coast? My father lives in PE and just replaced his two el-cheapo developer-spec geysers that lasted about 3 years before rusting and bursting, despite the porcelain-enamel finish.

Apart from coastal weather, high pressure is also what kills geysers, and I think that this is quite an innovative low pressure approach to solve the hot water problem, plus it can also be integrated with solar.  

Edited by YellowTapemeasure
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33 minutes ago, YellowTapemeasure said:

I think that it's quite innovative, fiberglass tank (low pressure), very efficient way of doing heat transfer, and because it's integrated there aren't long pipes to yet another geyser, and all the associated limescale issues. Locally manufactured and supported with a Japanese (not Chinese) compressor. Agreed that it's pricey, but I will probably be looking to replace my own heat pump with it when it breaks down (it's 6 years old already). 

Check out the explanation video:

 

So the guy around 2 minutes says how bad the polyurethane is at releasing heat to the atmosphere and then later on when he talks about the manufacturing process, he mentions how the fiberglass tank is enclosed in polyurethane and prevents heat escaping. 😂

Its new technology but anyone have any real life experience using it, especially in icy cold joburg temperatures. From what I understand you are heating the water in the tank and then the water that gets to your tap is basically flowing through that hot water in the tank and gets heated along the way, but the water in the tank is also cooling down at the same time. So how much of hot water can you really get out of it before you end up with Luke warm water. Seems like the hot water in the tank doesn’t mix with the water that comes out the tap. I guess for a 1 or 2 member household, this is sufficient but if you have many people then you could have problems as you don’t have  200l of water at 60 degrees. 

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19 minutes ago, YellowTapemeasure said:

True, that's also an option. How good is the Heattech geyser warranty though, and how well does it perform at the coast? My father lives in PE and just replaced his two el-cheapo developer-spec geysers that lasted about 3 years before rusting and bursting, despite the porcelain-enamel finish.

Apart from coastal weather, high pressure is also what kills geysers, and I think that this is quite an innovative low pressure approach to solve the hot water problem, plus it can also be integrated with solar.  

A Heattech comes with a 5 year warranty however many people forget to replace the sacrificial anode every so often which prevents a geyser from rusting. 
 

Yes definitely innovative. Would be more appealing if it was a bit cheaper. 

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