electric water heater

I have a fairly old electric water cylinder (maybe 80 litre) Im suddenly getting low pressure. Does anyone please have any idea for the possible cause ? Im thinking maybe rust is building up inside and os causing a blockage ? it doesnt have an expansion tank but I think has a pressure valve...

Hi everyone. I have an economy 7 quatz heater/timer. I dont seem to be getting any hot water at all. Timer light is on but unable to boost as the light on it dose not come on. Ive tryed turning the other big clock dial to different times like suggested on some of the other posts but it still...