I have recently finished having an old central heating system renovated and had a new combi boiler put into the system. The system feeds a double layer system one ring up stairs and one circuit for the down stairs radiators. My question is: do the systems require to run in a circuit? When the plumber finished the hot radiator feed never met up with the cold return on either floor. I have now joined the pipes so that at the end of each circuit the hot meets the cold and returns to the combi boiler, is this right? Any comment welcomed, thanks
