XTend Ceramic Elements

They can't even work out what is more or less energy...
"Additional energy required" notes 4/5 are NOT what they actually show... 4.8/6.44 - 1 = -25%... I.e. 25% LESS energy used, which is the same as 34% more (the other way around)

I'm pretty sure the problem with the "spiral" element is you get heat stuck around the element so then the element switches off too soon. As can be seen here -- the average dump temp is lower... But as you can see exactly the same amount of energy used -- maybe they just asserted "well they are both 2KW so must be the same". Or just multiplied 130 mins by 2kW -- which again would be 4.3kWh not 4.8kWh?

They didn't fix time or settings (one is at 50 one is at 60, different times left etc..) when making the comparison makes me think they probably asked someone to do a bunch of tests and pick the ones that worked.


The main source of "error" even if they deliberately did it fairly would be down to the "averaging" of the temperature at the end... What does that mean, they take a few readings and just average, was one of them maybe suited more to one system -- e.g. ignoring the first 10L because that is the hot bit stuck by the spiral element...

Most importantly this isn't an independent test. It would be quite easy to replicate this kind of thing just by maybe waiting a few hours for the ambient temperature to warm the water before starting the test. Or refill the geyser when the body of the geyser is already warm etc... I e. Do the ceramic element test last etc...

In short. I don't buy it ... Too many elementary mistakes.
 
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richjdavies said:
They can't even work out what is more or less energy...
"Additional energy required" notes 4/5 are NOT what they actually show... 4.8/6.44 - 1 = -25%... I.e. 25% LESS energy used, which is the same as 34% more (the other way around)

I'm pretty sure the problem with the "spiral" element is you get heat stuck around the element so then the element switches off too soon. As can be seen here -- the average dump temp is lower... But as you can see exactly the same amount of energy used -- maybe they just asserted "well they are both 2KW so must be the same". Or just multiplied 130 mins by 2kW -- which again would be 4.3kWh not 4.8kWh?

They didn't fix time or settings (one is at 50 one is at 60, different times left etc..) when making the comparison makes me think they probably asked someone to do a bunch of tests and pick the ones that worked.


The main source of "error" even if they deliberately did it fairly would be down to the "averaging" of the temperature at the end... What does that mean, they take a few readings and just average, was one of them maybe suited more to one system -- e.g. ignoring the first 10L because that is the hot bit stuck by the spiral element...

Most importantly this isn't an independent test. It would be quite easy to replicate this kind of thing just by maybe waiting a few hours for the ambient temperature to warm the water before starting the test. Or refill the geyser when the body of the geyser is already warm etc... I e. Do the ceramic element test last etc...

In short. I don't buy it ... Too many elementary mistakes.
Click to expand...
I don't buy it either, hence why I asked for independent opinions if anyone had used them. At the moment all we have is speculation (albeit well founded) as to why their claims are wrong. I'd love to see some real data from an independent source.

I wonder if I can convince them to sell me one with a money back guarantee if it doesn't perform as advertised after a week.
 
Actually... Just realised.

150L Geyser...
0.001166 kWh/Degree/Litre (waters specific heat capacity in kWh 4.2/3600)
=0.175kWh per degree... At 100% efficiency....

They are claiming 0.142?? So there's a problem? It's 120% efficient?!

Maybe it's just their big fat element uses up lots of space in the geyser??? So it's not longer heating up 150L of water, but only 120L?!

Easy experiment... When you're putting in the element just stick 30L of bricks in while you're at it!
 
I have the extend element, it does seem to use a bit less electricity, however it does not work well with my geyserwise timer, the thermostat reads lower than the actual water temp, my geyser overheated when i first installed the element until i figured out the issue,as initially i was using a normal thermostat.
it probably reads 15 degrees under the actual water temperature. The thermostat pocket probably needs to be designed better
 
were the geysers tested horizontal or vertical? big difference .your standard bent over element may also not be as efficient as a large spiral element .in some horizontal geysers the element turns off long before saturation point .for me 2kw is 2kw which ever way you look at it .for 2kw to outperform 3kw would be like ....perpetual motion ..but just in a geyser .PTC heaters are not new .they are used plenty in factories for heating surfaces etc pig farms .they can be made smaller in size but as for using less power .dont know.
 
I see no one has posted here i a while but to to add my 2c. I have the 2kw element for some time now but just recently bought a smart timer that has power meter reading function, and the power figures are out. They state steady current of 9A but I've to see above 6A. Avg around 6.4A @ 230V = 1472W. takes 4Hrs to heat my 150L.
So this isn't doing well for me on my solar as it take so long to heat the water.

1689709342659.png

1689709694572.png
 
marcocam said:
I see no one has posted here i a while but to to add my 2c. I have the 2kw element for some time now but just recently bought a smart timer that has power meter reading function, and the power figures are out. They state steady current of 9A but I've to see above 6A. Avg around 6.4A @ 230V = 1472W. takes 4Hrs to heat my 150L.
So this isn't doing well for me on my solar as it take so long to heat the water.

View attachment 1559009

View attachment 1559017
Click to expand...
Yeah. I don't see how these elements can change the fundamental physics involved. Snake oil if you ask me

Pt = (4.2 × L × T ) ÷ 3600. Pt is the power used to heat the water, in kWh. L is the number of liters of water that is being heated and T is the difference in temperature from what you started with, listed in degrees Celsius.
 
I wonder if the savings comes from turning your temperature down, in the installation instructions it says:

With XTEND elements it is possible to set the thermostat 10 to 15 deg C lower than standard.
Click to expand...

... That sounds like they are scraping the barrel for reasons. Doesn't matter what it's heated with, the temperature of the water is the same. Also they don't seem to be aware of listeria (a severe bacteria that can be found in geysers) which only dies at 60 deg C, so you don't want to set your as low as they recommend, unless you wish to risk getting

From their installation instructions:


1742830423650.png
 
fever2tel said:
I wonder if the savings comes from turning your temperature down, in the installation instructions it says:



... That sounds like they are scraping the barrel for reasons. Doesn't matter what it's heated with, the temperature of the water is the same. Also they don't seem to be aware of listeria (a severe bacteria that can be found in geysers) which only dies at 60 deg C, so you don't want to set your as low as they recommend, unless you wish to risk getting

From their installation instructions:


View attachment 1806661
Click to expand...
Yeah, those temps are right in the Legionella danger zone.

legionella-dangerous-temperature-chart.jpg
 
Fitted a 2kW Xtend to one of our geysers in 2023. Left thermostat temp at 55-60 deg.

It's set to run 4 hours per day and uses 6kWh during that time, thus drawing 1.5kW when on.

Previous ("standard") 2kW element used 8kWh during the same time, thus drawing the stated/rated 2kW, with similar hot water results.

The above all measured and controlled via the same smart breaker since 2020.

I had my reservations, but 2 years in, there appears to be an acceptable saving. The 1.5kW also works well on the solar.
 
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