Slow Bathroom Sink Drain - but Tub and Toilet Drain Fine
I am hoping that someone can offer a suggestion to solve my problem. We recently purchased a 60 year old home. The sink in one of our bathrooms drains completely fine until the water has run for about 5 minutes and then all of a sudden it starts to back up and then drains very slowly. I have verified that the trap, etc is completely clear.
My first guess was that there was a partial blockage somewhere down the line, but neither the toilet nor the tub in the same bathroom has any problem at all - and all other drains throughout the house experience no problem. Could this be a venting problem?
The bathroom is on the first floor and I can get into the crawlspace below. I have verified that the sink, tub, etc all ultimately connect to the same main line.
We are on city sewer and the pipes in this part of the house are galvanized - so I am certain that there is at least some corrosion in the pipes.
Thank you.
Thanks... used a power auger and it seemed to solve the problem
Thanks for the reply. The auger seemed to solve the problem - I assume that the corrosion inside the galvanized pipe had just caught hair, etc somewhere down the pipe and slowed it down considerably.