1.   Opening the drain valve at the bottom of the water heater will not remove the filings.

2.   After all the water is out, close the drain valve and open the inlet valve coming from the boiler.

3.   After the tank has been drained, close the drain valve and vacuum-breaker plug then open the shutoff valve.

4.   Both systems have drain valves at the base of the furnace.

5.   Drain the water until it runs clear, then close the drain valve, open the supply valve and turn on the furnace.

6.   Now position a bucket under the boiler drain valve.

7.   The drain valve is usually at the base of the furnace.