Ho wlong does hot water stay at max temp (within 4 degrees) in a boiler?

[John.g]

Came across this some years ago so calcs may be done for various cylinder volumes.

I have seen cylinder losses as low as 0.25C/hr claimed for some cylinders, mine (150 Litre) is 0.45C/hr.

Hot Water Cylinder Loss​	​	​	​	​	​
Kwh/24 Hrs at 60C​	1.6*(0.2+0.051*V^2/3)	where V is the Cylinder Volume
​	​	​	​	​	​
Cylinder Volume​	210​	Litres​	​	​	​
Heat Loss​	3.20​	Kwh/24hrs​	at 60C	​	​
Heat Loss​	13.12​	DegC/24hrs​	at 60C	​	​
Heat Loss​	0.55​	DegC/Hour​	at 60C	​	​