All pumped central heating system using 2 2-port valves to control Heating & DHW. Replacing boiler, pump and controls soon what are the merits of 2 x 2-port valves versus 1 x 3-port diverter valve.
If I stay with 2 x 2-port valves and have TRV's on ALL rads do I still need a small bore bypass around the boiler to help it dump the remaining heat when the 2 x 2-ports close.
If I stay with 2 x 2-port valves and have TRV's on ALL rads do I still need a small bore bypass around the boiler to help it dump the remaining heat when the 2 x 2-ports close.