drain hydronic system to replace baseboard heater
You will probably have to turn off the furnace and open the valve on its boiler to let the water out that way.
You cannot drain just one zone unless it has manually operated shutoff valves on both the outgoing and return pipes as well as a drain valve within the closed off section.
The disadvantages of crab apple trees. In summer, the apples are too sour to pick and eat. In winter the birds come and leave dropping all over the place.