Hello,
I have recently brought a 25 year old property with electric heating provided by means of storage and panel wall heaters (original). There is an insulated hot water tank with dual electric immersion heaters. Would you recommend any sort of cover for these. Also, how often should I get them checked?

Would you recommend any sort of cover for these. Please explain! Are they located outside? What area do you liven in? If they aren't outside why would they need cover?

Also, how often should I get them checked?
Your water heater should be flushed monthly. Let me show you how.
For long life and fewer troubles you should keep your heater clear of mineral build-up by FLUSHING NOT DRAINING on a regular schedule. Attach a hose to the boiler drain at the bottom of the tank. With the pressure on, open the boiler drain and let it run until the water runs clear. You will see a spurt of red,(rust) followed by white or yellow grains,(lime or calcium carbonate). This shouldn't take more then a few minutes. Do this monthly to keep it clear. Now flush out your hot water lines on ALL fixtures that are affected . Now pull each aerator and clean the screens. Be sure you put them back together the same way you took them out. Don't forget to flush it out every month. Your heater will thank you for it.

electric heating provided by means of storage and panel wall heaters
I have electric heat, ( heat strip) myself but tell me more about this "storage". Is there a furnace installed? How and where do you "store" heat? Back to you, Tom