Changing a vented hot water system

[audi321]

Hi all. I have a flat where the hot water is a strange vented type, whereas the header tank is attached to the copper tank directly below it.

In view of this, I was thinking of changing it to an unvented system. Is there anything preventing me doing this?

There's good cold water pressure and the only way to heat the water is an emersion heater.

Any ideas/tips?

Thanks

[audi321]

Why do I need a qualified plumber?

I've got a cold in and a hot out and an immersion heater. Surely that's a simple install?

I get the hot water expansion part is the risky bit, but don't these unvented tanks have some kind of 'built in' pressure relief solution?