I have a storage heater which is playing up, and was trying to find out the element resistance values and circuitry in an attempt to diagnose the problem, and was directed to this site after searching Google.
Most domestic storage heaters are made up using multiples of 850watt elements. Range from 1 to 4.
1 element. if you divide 850 by 230 = 3.69Amps.
230 divided by 3.69 = 62.33 ohms.
3 element. divide 2550 by 230 = 11.09Amps.
230 divided by 11.09 = 20.74 ohms.
And so on.
These figures are based on a nominal voltage and may not reflect your voltage. Should get you readings close enough to know if it's ok.
Mains in is usually fed up to a charge controller (thermostat) on the top right and back down to the elements. This can often be the problem as the elements are quite reliable.