What is controlling the solenoid? Just a thermostat? What is the output voltage of that device and what is the input voltage needed for the solenoid? Should say right on the body of the coil.
Water always on, look on the side of the body of the valve or on the bottom, there should be an arrow. That shows flow direction, if backwards it won't hold the water back. The arrow should be pointed from the source to the bay lines.
Where do those yellow bay lines connect? Above the bays in a manifold? Personally I would have them T into the HP line in the equipment room (with a check valve between them and the HP connection).
You say the blue hose on the right comes from the two bays, there must be a T somewhere before the picture? There's only one hose. When you say it comes from the bays, what do you mean exactly? What do they connect to?
I don't think you need to start all over, but there are some complexities you could remove from the setup there. If you have a NO valve, then voltage needs to be applied all the time to keep it closed when it is above your set temperature. When the ambient temp drops, then you want the voltage to disengage which will open the valve. Note, when you are done having freezing temps, I would turn off the voltage and the water supply to the valve so you don't incur wear and tear on the solenoid and cook it all summer long.