Toilets On Same Wall Flush One And Level In Other Goes Down

SJS947

House is 35 yrs old. Have lived here for 30 yrs. Never had this problem until last week. The second floor of my house has a main bathroom and master bathroom that share a common wall. The toilets for each are basically back to back on opposite sides of the shared wall. When I flush the toilet in the main bathroom, it drains about half the water from the bowl of the toilet in the master bathroom. But flushing the toilet in the master bath has no effect on the toilet in the main bath. Any ideas? Thanks

DannyT

are both bathrooms original to the house. what happened last week? was any work done to the plumbing? sounds like a venting problem to me or the line is partially clogged and when the water drains out of the pipe it is siphoning the water out of the other toilet.

Msradell

Assuming no other plumbing work was done is definitely a venting issue!