Hot water /central heating question

[Froggies]

Hi,
I am a student, and currently trying to get my head around ho****er and central heating systems. I am a little confused, and struggling to find the info clearly stated anywhere; if you have a direct hot water tank that is heated from a boiler, can you also attach it to a central heating system? I think that you cannot, and you need to have an indirect system to also have CH, but would like this to be confirmed (or not!) as I have an assessment on this next week!
Thanks for your help in advance

 

[SimonJohns]

You would not have a direct heated cylinder with a boiler. A direct cylinder would be that heated only by an immersion etc

When you have a boiler that heated the cylinder using pipes then the cylinder is indirect

 

[Froggies]

Ok, thanks. I am assuming that you would not run central heating off this, central heating by immersion element would be scarily expensive!

But, (I have an ancient house) when I moved in it had a solid fuel rayburn that heated the water in the tank upstairs (there was no electricity supply at the time) and obviously no radiators. when I put central heating and electricity in, I was told I would need to replace the hot water tank as there was no coil inside it (which I thought meant it was a direct heated tank). Maybe this is why I am confused?

 

[Mike Jackson]

It was common practice to use a direct cylinder with a solid fuel boiler. You will also come across gas fired circulators connected to direct cylinders. In some instances towel rails were fitted to direct systems but they needed to be copper or brass otherwise they will corrode.

On a direct system the constant replenishment of the water would cause major corrosion to normal radiators.

 

[Froggies]

Ahh, thank you, that clears the confusion.
Phew!