We've a full bath (combo shower/tub, lav and toilet) where the tub either does not drain at all, or will take 48 hours to finally go down (when aided by chemicals I know I should not be using). The lav and toilet have no flush/drain problems, so I'm not thinking it's a bad vent situation... could it be?

Replacing the tub and/or plumbing is a major effort given the location of this room in the house. Had a plumber out a few months back and he said he needed to remove it do get a better look at the piping to tell me what was wrong... which seemed like a bad idea (can you really remove the unit and put it back?)

Any ideas on what might be the problem? Any thoughts on a less invasive way to fix it? It's our kids' bathtub and it's annoying to not be able to bath them there everyday.

Thanks, Matt

Good morning Matt,
(Had a plumber out a few months back and he said he needed to remove it do get a better look at the piping to tell me what was wrong... which seemed like a bad idea (can you really remove the unit and put it back?)
A licensed plumber told you he would have to tear up a tile wall and pull a bathtub out just to "look at the piping"? UNBELIEVABLE!! I hope he's no longer your plumber and that he's back "flippin burgers" where his plumbing skills would indicate he belongs.
I can tell you what's wrong and how to fix it just setting here at my computer and without ever seeing your bathroom, let alone pulling your tub.
Have you any Idea what the cost of taking out a tile wall, pulling the tub and replacing it would be. So he got the tub out. What then since the pipes are located under the floor?
Sorry about going on but it leaves a bad taste in my mouth when I see a "fast track" plumber attempting a rip off using such a lame and stupid excuse to do so.
Having vented about that let me address your problem.
Hair mixed with grease is the main cause of bath tub blockages. To solve your problem simply snake out the tub drain. This can be a project for a homeowner if you wish. You have two options here. You can call in a plumber and snake out the tub branch or I can walk you through the process.
Your call! Just let me know. Tom

Tom,
Would love to get your help on how to approach this. I'm more than comfortable working on it myself (with your guideance of course!)

In case it matters, I can't get down the tub drain (it's not showing any signs of budging), I would need to go in via the overflow.

Looking forward to clean children!

Bob

You can't get through the tub drain, you have to go down the over flow. Let me show you how. Unscrew and remove the overflow plate,(The one with the drain lever) and pull out the tub stopper. You now have a clear shot at the trap. That way you aren't going in through the drain, it will run you square into a tee that you can't get around. Now feed the cable( 1/4" best or 3/8" with a small tip. You can rent a Ridgid K50 drain machine or simply purchase a hand crank snake.. ) About 2' down you will run into the bend of the trap. Crank and push at the same time to work around it. Your blockage will be found in the lateral pipe going to the stack. You shouln't have to put out more then 10 or 12 feet. I have found tub and shower clogs to be mostly hair and the worm should auger into it and pull it back. Hope this helps . After you are through augering, pour a few large pans of boiling water down the drain to loosen up and flush out any grease and hair that might be left. Good luck and if there are more questions I'm as close as a click. Tom

Speedball1 - thanks for the instructions on snaking a tub drain. I'm having the same problem of a slow drain and tried snaking the drain from the overflow tube. However, I can't seem to get past the elbow where the vertical pipe changes to horizontal. Any advice or tricks on how to do this? I gave the snake steady pressure while cranking, but couldn't get past the elbow, even after 15 minutes. I do live in an older house and suspect I have a drum trap, but I don't think I'm getting close to the trap.

Since I never sent the closure note for this, I guess this is as good a time as any...

So my real problem turned out to be a MASSIVELY corroded elbow. I tried to get an auger in there and couldn't get more than a few inches and just head it chunking on what sounded like metal.

My task in the end was to cut out the trap and replace it (luckily I could access the plumbing via a newly installed access panel in the closet behind the bath!). It was a ugly job, but it cleared it right up.

I'm sure it's not code, but I'm not licensed either!

Good luck with your job, Matt