I seem to have a recurring, and puzzling, sewer problem. About 6 weeks ago, I had tub drain gurgling for several days, then a backup when the toilet was flushed. Sewer cleaner went thru the roof stack, said he used 180 feet of cable, found roots, etc. All seemed well.
Three days ago, the gurgling started again. Definite smell of sewer gas, but no backup. Got the sewer guys out again. They could not get cable through from the roof (obstructed at about ground level). They pulled the stool, 150 feet of cable, yada yada, all was well for a day.
Yesterday, more gurgling, this time in response to either toilet flushing or kitchen sink emptying. LOUD, extended. Gurgled every time either was drained, all day yesterday, all night, first thing this morning. All drains seemed to be working fine.
Later this morning, I took a shower. No more gurgling upon flushing or draining.
My theory: There is an obstruction somewhere around the vent (which might account for why team #2 was unable to run cable via roof stack). The drains hold enough water to keep the trap full for a day or two, but flushing eventually empties the trap and gurgling starts. Showering this morning refilled the drain, which refilled the trap.
At the risk of making a horrible pun, does this theory hold water? If so, any suggestions for how to fix? If not, alternate theories?
Thanks in advance, Jo Ann