In our recent reno, we wanted to replace the existing kitchen faucet. Also, we had a leak at the clear-out at the bottom of the p-trap. We had our plumber take a look at it and he said that the trap needed to be replaced. So we said to go ahead. While doing the fix he said that whoever had roughed in the plumbing from the wall had done it wrong, and the pipe came up too high, and that to compensate they had installed a second p trap. He asked if our water had been draining slowly, and indeed occasionally it had.

http://img638.imageshack.us/img638/3389/doubleptrap.jpg

He did the fix and then said that he could potentially redo with different piping to eliminate the second trap -- I'm sorry, I don't remember exactly what he said he would do to achieve that. With the new installation it seems to be draining fine, and so I'm inclined to leave it alone, although I realize we have two potential failure points instead of just one. Thoughts?

Hmm, just looking at the answers to a similar question, I see that this may be more of a problem than I thought.

Two traps is a bad idea, the second trap can siphon the water from the first trap and also cause slow draining. Lengthening the verticle brass drain pipe down about 3" more would get the trap to line up with the horizontal pipe coming out of the wall. I would do it.

Wow, how much was all that chrome and brass? These days people put in a thin PVC kit joined to old copper or brass waste pipe with a rubber sleeve with hose clamps, all for about $10 DIY, and the PVC slip couplings let you just quickly take it apart instead of having a drain plug. If the waste pipe is too high you simply cut it down. But you can just leave what you have the way it is.

But you can just leave what you have the way it is.

Actually no you can't. 2 traps is not correct and should be fixed as outlined in my earlier post

Thanks for your replies. I definitely realize it's wrong and not to code, but I guess my question is related to the seriousness -- is this a "fix it right now" kind of thing, or a "fix it once you get sick of the slow draining" sort of thing?

W/r/t the copper & brass, I live in Brooklyn and NYC has much more restrictive codes about the use of PVC than anywhere else in the country. Even so I think it would have been legal to use in this instance, but plumbers here have the reflex to use metal. It didn't cost all that much, anyway.

You have a "P" trap connected ton a running trap and that's illegal in all codes. This is not a danger as the running trap will still retain a seal but I would have it repaired in the near future and Bob suggested. Good luck, Tom

Just so I understand, the danger is that sewer gas will escape back up the pipe?

Just so I understand, the danger is that sewer gas will escape back up the pipe?
Yes! The suction caused by the draining water will suction out the first traps seal but unless you can smell sewer gas out of the drain the rtunning trap should still retain a water seal. You don't smell anything do you? Let me know, Tom

OK sorry, you shouldn't leave it but it's not an emergency

2 traps are no good. One of them has to go...

Milo's correct and the one to go is the running trap, Tom

What do you mean by running trap? Thanks

QUOTE=;]What do you mean by running trap?[/QUOTE]
A running trap,(see image) is the trap next to the wall. Regards, Tom