Main Drain Air Lock

JPMorgan

Well-known member
May 22, 2018
207
Elmhurst, IL
I'm looking for advice from someone with experience doing an air lock on the main drain. I am doing this when I close this year. My pool has the main drain line coming from the bottom of the pool into the skimmer. I installed the proper plug in the skimmer and then let the compressor rise to about 60-80 lbs of pressure. I then put air in the line and waited until I saw bubbles coming from the main drain (which took about 10-15 seconds). After I started seeing bubbles I continued putting air in the line for about 20-30 seconds. Does that sound about right?
 

1Sammy

In The Industry
Jul 20, 2017
403
Windsor, Ontario. Canada
I'm looking for advice from someone with experience doing an air lock on the main drain. I am doing this when I close this year. My pool has the main drain line coming from the bottom of the pool into the skimmer. I installed the proper plug in the skimmer and then let the compressor rise to about 60-80 lbs of pressure. I then put air in the line and waited until I saw bubbles coming from the main drain (which took about 10-15 seconds). After I started seeing bubbles I continued putting air in the line for about 20-30 seconds. Does that sound about right?
And then what did you do ?
 

JPMorgan

Well-known member
May 22, 2018
207
Elmhurst, IL
Nothing else after that.... just put the cap back on the air valve in the winter plug and put some anti-freeze in the skimmer along with a half full bottle of anti-freeze to protect the skimmer.
 

1Sammy

In The Industry
Jul 20, 2017
403
Windsor, Ontario. Canada
Nothing else after that.... just put the cap back on the air valve in the winter plug and put some anti-freeze in the skimmer along with a half full bottle of anti-freeze to protect the skimmer.
ok got ya. I thought you were like Flash Gordon and removed the air plug real quick and put in a plug. Watch for very small bubble around your plug / air valve as lots of pressure down there trying to get out now and a very small leak can push out all your air over the closed months which will let the water level rise.
 

JPMorgan

Well-known member
May 22, 2018
207
Elmhurst, IL
I do check for air bubbles coming from the plug in the main drain line to make sure I have a good seal after I have pumped air in the line. I'm assuming everything is good if I don't see any bubbles at that point. I rarely check it after I have closed. Should I keep checking for air bubbles throughout the fall, i.e. weekly? (If I did spring an air leak, I'd have to catch it before all the air leaked out. I'm guessing that could happen fairly quickly, however, and then I wouldn't really know if I still had a good seal or if all the air had leaked out.)