If I have 2 x 2 port valves, means one for heating and other for hot water,
must I have a by pass valve? otherwise when both heating and hot water
valves as shut, there will not be any path for the water to flow. This pumped water then should flow through the by pass valve that should be open fully at this stage.
Should the signal that switch the boiler off should also switch the pump off
as well rather than through the boiler as a "run over". In this case it will
not switch off the pump till the heat exchange cool down to certain temperature?
must I have a by pass valve? otherwise when both heating and hot water
valves as shut, there will not be any path for the water to flow. This pumped water then should flow through the by pass valve that should be open fully at this stage.
Should the signal that switch the boiler off should also switch the pump off
as well rather than through the boiler as a "run over". In this case it will
not switch off the pump till the heat exchange cool down to certain temperature?