I am purchasing a home and an inspection was performed. Built in 2006. Cpvc supply lines and PVC drain and vent lines. Both toilets in the home have an air pocket when the toilet is flushed, however otherwise they operate normally. A plumber came out and snaked the drains and clean outs and there were no obstructions. The plumber stated on his report that the bubbling could be caused by an air tube at the water closet p traps. Does this sound correct?

air pocket when the toilet is flushed

There is no such thing.


an air tube at the water closet p traps..

There is no such thing.

If toilets are bubbling when flushed, that would be caused by a blockage or partial blockage in the drain line. Water flowing down the pipe is forcing the air in the pipe back up through the pipe and the toilet bowel. Plumber didn't snake far enough or didn't clear the blockage.

If toilet is gurgling (like a coke bottle turned up side down) the vent pipe is blocked.

Air tubes in the bowls P-trap? First time I've heard that one. For what porpoise? A much more logical explanation would would be that he missed the partial blockage that's causing the blowback causing your bubbles of sewer gas. Are you on city sewer or a septic tank? Back to you, Tom

It's on septic. It has already been inspected and pumped. No issues. It's just one bubble once it is flushed. Could it be a defect with the toilets?

flushed. Could it be a defect with the toilets? I would be happy with that if only you hadn't told me that BOTH toilets were blowing bubbles at you.
Let me explain about blowbacks. When a toilet flushes the water rushing down the pipe sets up a vacume in the system. This vacume is relieved by leting air in from the outside. Hence the vent. You should not feel any pressure coming out of the vent at all. This is called "back pressure" and is caused by water and solids hitting a partial blockage, stopping and backing uo sending a wave of air back up the vent. Then since the passage isn't completly blocked it drains away. Now this doesn't necessarily have to be in your system. A partial blockage in the city main could cause back pressure during peak load periods. This however would affect your neighbors as well. Drainage systems are designed so air flows one way, out. It's possible that the contractor that tied your sewer to the main left you with backfall or a blockage at the city raiser, (the connection from your sewer to the main.) I would call the city to see if there has been any other complaints. If not I would call my contractor back and tell him your problem. Back pressure is not normal in a drainage system and don't let anybody tell you that it is. If it started when he ran the new sewer line then somewhere along the line he set up a back pressure problem. Hope this helps and thank you for rating my reply.

This home is on septic and well. So no city sewer or municipal water supply. And also, I have never heard if an air vent in the water closet.