I have a 2 bathroom house, and the master bathroom is the most "upstream", further downstream is the 2nd bathroom, then further down is the laundry room tie in, then the kitchen tie in, then out the street to the city sewer.
All the toilet seems to flush normally. But when my master shower is on, draining a lot of water into the line, the 2nd bathroom toilet water level drops slowly, then it does the bubble burping thing. Once the master shower stops running, wait a little while and the 2nd bathroom toilet flushes normal again, at least as far as I can tell.
I understand when the master shower runs, it dumps a lot of water into the line, and pushes some air down the line too. This air as it goes through the 2nd bathroom tie in, will go up that line and normally escapes through their vents. But instead it chooses to bubbles throught the toilet.
Does it mean there is full or partial obstruction in the line downsteam from the 2nd bathroom?
My kitchen sink seems to drain well, but that is not a lot of water when I use it.
So I go to the 2nd bathroom and there is a sink, a shower and the bubbling toilet. I turned on that shower in there, it does not make the toilet bubble. Tried the sink too, only the toilet seem to bubble, nothing else. Wouldn't the shower and sink also make the toilet bubble? Unless they are both upstream of it, but I cannot tell since the last owner did some major remodeling.
Where should I begin my diagnostic to know what to do? Could it be a blocked vent stack to the 2nd bathroom toilet? Could that be the cause? or is partial obstuction be most likely the case.
I would have called a plumber but I like to know more what is going on first before making decisions. A few years ago I had a clogged line and I called a plumber and they came, removed my toilet and send an electric snake down, it cleared the clog, but in the process splashed what my wife called a "shit storm" on all the walls, ceiling, medicine cabinets, shower doors, tooth brushes, towels, linens etc... and she almost made me move because of it. Later she found out that they could have done the snaking from the outside cleanout or from the vent down...it was trouble for me.
Thanks for any advise.
S