How to bypass this component to a Tetco Heat Pump
As per @Lukus , that unit is a geothermal heat pump that is using well water to provide for an approximately 55 degree source water. Wow, what a waste of good water! If the device you are speaking of is the item on the left side  with the gray top and the spring it is temperature sensing control valve, probably made by "Johnson Controls", that maintains a given set point temperature, at the sensing bulbs location. (NO, it is not a solenoid valve) . If you bypass this device you will affect the heat-pumps operation, good or bad, I don't know, and you will probably use much more water. A similar model number of this control would be V47AA or AC. AS for a solenoid valve I do not see one in either picture, but there probably is one somewhere. Item last; the people you called that originally installed the unit are probably not the same people that run the company now. Their advice on how to proceed was not in your best interest and shows that they have little knowledge of your installation.