The toilet in my old house is not flushing properly, it has a window but no ceiling vent. Does that really make a difference, it has worked fine for years, we had a new toilet installed last month?

Hi Ldrae...

My guess is that it is more likely that the new toilet wasn't installed properly. It is possible that the wax gasket has intruded on the waste pipe and is causing issues with the flush.

I would:

1) snake the toilet with a closet auger... see if that improves things.

2) lift the toilet and install a new wax gasket. Hopefully, that will fix it.

Finally, before you proceed check the plumbing VENT serving the bathroom. The plumbing vent sticks out the roof and should be between 12-24" tall. If this is clogged it could definitely cause issues with the flush. The ceiling vent is not an issue here.

MARK