Normally you would not mix your potable hot water and heating water, but who knows what folks do in Turkey. I actually spent about two weeks there a while back going all over the country. Unfortunately, that was the last time I was a millionaire (in Turkish Lira). Great country though. Though, I did not pay much attention to the wiring and piping of their boilers. I am not entirely clear on your set up. Is there a hot water storage tank or just the boiler? Do you have the manual for the boiler?