Electricity bill

Hi Mike,
I have lived in my flat for 8 years and have a PulsaCoil III. Recently I have noticed my electric bill go up massively (More than in keeping with prices). My units used on average range from 20-45 units daily. I was discussing this with my neighbour who told me to turn my immersion heater off as it was continually reheating the water. Scottish power told me that the immersion would be using lots of energy. So i turned it off. The two switches,one has a red light - is the one i have turned off, the other is just a switch and remains on.I have been told that our boilers do not have the Economy 7 settings connected.

So I guess I have two questions:
How do i use this boiler so I can have hot water when I need it and it be most energy efficient?
Do you think that changing my use of the boiler will reduce my bills?

I fill up my smaller 'top up' tank roughly 1-2 times per month and there is a large deposit of limescale on one of the pipes leading from the small tank to the big tank. Will this affect the boiler?

Thanks for reading the rant and i hope it makes sense :-)

Any thoughts on my previous posts

If you are filling the tank up 1-2 times per a month, this is worrying the system is more than likely leaking. I would recommend you inspect it for leaks.

Now in regards to reducing your utility bill. You don't have a separate eco 7 supply but do you have two rates? if you have a cheaper rate at night, I would recommend you have a timer installed, set to the same time as your rate 2.

Also just request this free self check guide which maybe able to help you understand settings a bit better, use this link: Pulsacoil 3