home repair, interesting problem

My brother in law installed a toilet in his basement. Everything seems find, except that now the toilet on the 2nd floor works, the toilet in the basment works, but the toilet on the first floor won't flush. He took a shop vac up on the roof thinking he needed to clear a bird nest out of the vent pipe. THere was no bird nest. He did find out that while he had the shop vac running the toilet on the first floor would flush. What has he done wrong?
Norm
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
web_djs wrote:

More info: What does "doesn't flush" mean? Does the bowl overflow? Water swirls around? How was the basement toilet connected into the drain?
Simply adding the toilet, either with a TEE/WYE, or hacking a hole in the pipe should not have affected the upstairs toilets. Even not venting the basement fixture would have zero effect on upstairs flush.
Suspect either debris in the pipe or...problem in the 1st toilet itself.
Try the bucket test: Rapidly dump several buckets of water in the first floor toilet. Does the water go right down??
Jim
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@netscape.net (web_djs) wrote in message

If the toilet works with added draw on the vent, it must be a vent problem. No one can diagnose the problem without knowing the pipe layout.
TB
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.