NO hot water / Tarrif 31

1 Reply 1068 Views

Hi everyone,


250L hot water cylinder is great until approx April "every year", then no or very little hot water after 3pm.

Nothing has changed within the household, just running out of hot water. Cylinder is new & full. What gives?

Our need is for showers 6am - 8am and 3pm to 9pm, please help!!!


Cheers, Debbie

0 Replies 1057 Views




The issue is not with AGL and will occur with any retailer.


What you need to do is change your showering methods especially in the Cooler months.

It's nice to have a HOT shower, but do you really need a LONG HOT shower.


Is your shower fitted with a WATER SAVING SHOWER HEAD?


Say for instance your shower runs at 7 litres per minute then you will consume the 250 litres in about 28 minutes.


So that is 4 * 7 minute showers!


Now once the tank has heated overnight and your controlled load switches off you only have the heated stored water until the next heating cycle.


Now in the morning period (0600-0800) say you use 125 litres of hot water.


Hot water systems work on a very simple system, if you put cold water in at the bottom hot water comes out the top. (Turning on the hot tap is the process).


So after you have used that 125 litres, the replacement water is cold (relative to the hot water in the tank).


According to the second law of thermodynamics, heat will flow from the hot environment to the cold one as the temperature difference is equalized by diffusion.


Therefore you will suffer a temperature loss in the storage tank between the hours of 0800 and 1500 as the water temp tries to equalise. (There is not a proper mathematical law that calculates this)


Now, you mention that this occurs starting from April, so your feed-in water is getting colder.


You can always push the booster button on your Electricity Meter (after 0800), to heat the water you have just added. Be aware when you do this you will be heating the water at your current rate not the Off Peak or Controlled Load tariff.


If you have Solar and push the button the power will be consumed by your Hot Water service and not be exported to the grid.


By pushing the button at an early time you will only be basically heating the water you have just added. (Thus saving the amount of power you are consuming).


Obviously though, your 250 litre hot water system in not the right capacity for your household needs and as stated above you need to either change your showering habits (new water saving heads, reducing the temp and duration of showers) or replace the hot water service with a larger service.


Other things that you should consider is washing your clothes etc in cold water, reviewing your washing machine (Front loaders use a considerable less amount of water and most these days only have a heating element to bring the water up to the desired temp) and the use of your Dishwasher.


Hope this all helps.


If this resolves your issue please solve this.


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Cheers Neil.

Cheers Neil

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