How to drain baseboard heat system

To drain your system first shut off the gas and electric to the boiler then shut the water fill valve off. Turn the thermostat off or to its lowest setting. Attach a hose to the boiler drain at the bottom of the boiler and open this valve. If you have air bleeders on your radiators open the ones that are highest in the system to let air in so not to draw a suction as the system empties. As the water level in the system lowers gradually open the bleeders on the remaining radiators.