Posted by Harold Kestenholz - Hydronic Network on December 21, 2000 at 20:28:21:
In Reply to: Burnham Boiler posted by GM on December 21, 2000 at 18:52:50:
If there is no other valve in the system, the water is moving the air out of the system by the power of the circulator. If this has effectively eliminated the air and you have a quiet system, the purge has been sufficient. It is suggested in some codes to have isolation valves near the boiler to provide service without having to drain the system. The union and drain cock make purging easier. These are niceties that most installations have done without. If the system is quiet and heating well, there is no cause for alarm. I prefer to follow manufacturer's instructions.