Cistern Water Heater - heat loss

amtrakuk

Does anyone know the 24hr standing heat loss in a 75 litre cistern water heater?

I have been googling for a few days and can get figures for cylinders. All I found for cistern water heaters is typically, "Injected XYZ insulation for minimal heat loss", I've even searched the manufactures website as well as phoning the manufacture with no figures. Not much help, does anyone know what the typical figures are.

Cardew

It will obviously depend on the water temperature. However 'normal' domestic hot water tanks around 150 litres are tested to a British Standard with water @ 65C and typical losses in 24hrs are 2kWh.

So a guess might be 1.5kWh at the same temperature???

amtrakuk

Thanks and good to see you again Cardew...

Thinking of moving from the Redring Powerstream to either a ZIP RCH 75 or I think a mate could sort a 216 litre Navitron thermal store. Just comparing running costs between the 2 systems. The thermal store would be better for performance but to keep 216 Litres of water hot would surely cost a lot despite modern levels of insulation.