Then add sugar in one big dollop(I used to add a little sugar at a time but found it made no difference if I just chucked the lot in) and stir away(I use a stick thats an offcut from Hivemaking).
The sugar cools the water so bring it back up until the thermostat kicks in on max,continue to stir all the time from when the sugar is added.
I leave it overnight to cool.
Next morning you can see the bottom of the urn.
I put into 30lb buckets and add a couple ml of readymade thymol solution.
The only problem I have ever had is if you empty the urn of all sugar and leave it for a few hours without a rinse the tap goes solid and is a b*gger to undo without using a pair of molegrips and something up the spout to stop it spinning.
I did a mix yesterday,8 litres of water and 16KG of sugar.
my wife found me a large whisk thingy, like you use for gravy only bigger, works great, 10 litres 20kg on my 19th 25 kg bag, burko is the best way and leave some water in the bottom to keep the tap free