A call to a drain cleaning company did not help. They looked down the drains of the three year old home with a camera scope, all the way to the city sewer and found no blockages. The home owners were perplexed and called us for a “consultation“ to look at their plumbing and try to find the issue and determine a course of action.
The ranch home with unfinished basement made it easy to inspect the drain pipes which all looked good. Then we went up on the roof and the culprit was obvious, the plumbing vent pipe was capped (sealed) off for the plumbing inspectors pressure test. At the time of construction all drains are pressure tested for leaks, after they are passed, the cap must be removed from the vent pipe.
All it took was to break open the cap on the top of the vent pipe to let air in and everything worked properly. The cap worked the same as holding your finger over the top of a drinking straw in a glass of soda, you can lift it out of the glass without loosing the liquid, take your finger away and it drains out.
Vent pipes must be opened after the plumbing inspection.