Noise in sink when flushing toilet

[taylorsh03]

I recently had a bathroom remodel and one thing that was done was going from a single sink to a double vanity. After the work was done, I noticed when I flushed the toilet I would hear a noise in the left sink. After googling there appears to be 2 possibilities. One says there is a vent on the roof that may be blocked. The other says plumbing for the sink may not have been done properly. I have attached the pics of the plumbing. Each sink looks like it has different plumbing underneath. I am curious if this looks ok and it may be the vent needing cleared or if the plumbing was done improperly. Thanks

 

[Geofd]

The sink with that “flexible???” Trap should at the very least be turned down so it’s basically level
Usually the piping coming out of the wall right to the sink tailpiece is schedule 40 pvc with cleaned/glued fittings
Was the wall opened to make alterations on the drain and water
Looks like under one sink the hot and cold are not were they should be

 

[taylorsh03]

Going from the single to the double vanity, he did say that he needed to make adjustments to move the plumbing. He said that because the vanity has middle drawers it did not allow for a T that he would normally do. The pics are what we ended up with.

 

[havasu]

You need to fire that "plumber" as the same thing was done at my house. It is the lazy way, he split the water lines, and joined with the flexible accordion line, which is now similar to an "s" trap. If and when you sell, a home inspector will be tearing that job apart.

 

[Helper Dave]

That flex trap is likely getting siphoned out. What a terrible job. I don't know where it's code approved for a real plumber to put that garbage in. Who did the work?

Hire an actual plumber to fix that.

 

[Jeff Handy]

It also looks like both your drain tailpieces need a short extension piece, right now they are barely reaching the traps, and the traps are shifted up to reach them, leaving them crooked.

 

[Jeff Handy]

That bendy straw trap is sometimes ok for a day or two, if the correct parts are not in stock during a plumbing emergency.

But they plug up with hair and grease, and as was said, yours looks to be likely to siphon itself dry.

 

[Jeff Handy]

I also suspect that he ran one of the traps directly into the drain line behind the wall, without bothering to add a connection up and over to the vent at the original location of the old sink drain.

So it is probably wet vented, and that can contribute to it sucking its trap dry.

You might be ok by adding an air admittance valve on a short riser, to the trap arm of whichever trap is gurgling.
The gurgling trap is likely the bendy one.

 

[taylorsh03]

Thanks for all of the great responses. Hiring a plumbing company to come correct the previous work.