[Yodaman]

Changed WC1 over the weekend. Now we have a pretty good gurgle at WC1 when WC2 is flushed. Apparently the the trap and water level is lower on the new toilet, so less pressure to hold back the thrust of air when the WC2 is flushed.

pic 1 is the current layout, pic 2 is what I am considering. Any thoughts?

 

[Ghostmaker]

You can't use any fixtures not on the same floor as your wet vent on any fixtures that is called a stack. You also cannot tie anything within 30 inches of the base of a stack.

The bottom picture needs a vent on the tub. And from the stack 90 horizontal you cannot tie in the tub within that 30 inch zone. Also make real sure your using an air admittance valve not a cheater vent with a spring.

 

[Yodaman]

You can't use any fixtures not on the same floor as your wet vent on any fixtures that is called a stack.

Could you clarify this a little.

I did change the layout to pic 2 with exception to the tub which is tied in ahead of the of wet vent 90. The current pic shows it behind the 90. It is more than 30".

Also make real sure your using an air admittance valve not a cheater vent with a spring.

Yes, I am sure that is what's on there. I will change it.
But don't think that is going to help with the gurgle.
We ran a test, by removing the 1 1/2" clean out plug. When flushing WC2,
the water in WC1 was nearly still. Think I need to tie in another vent.

But what ticks me is the old toilet had no issues.

 

[Ghostmaker]

Could you clarify this a little.

I did change the layout to pic 2 with exception to the tub which is tied in ahead of the of wet vent 90. The current pic shows it behind the 90. It is more than 30".

Your drawing shows a drop with WC2 Lav2 Is this coming from a different floor? And is that vented out the roof? If it is coming from a different floor it is a stack and is not any type of vent for the lower fixtures on the lower floor. If you have no vent out the roof for fresh air. Your AAVS only suck in air they seal tight on the positive pressure thus the gurgling you are experiencing. On drawing 2 add a vent on the tub to air. Or vent the other lower bath to air.





Yes, I am sure that is what's on there. I will change it.
But don't think that is going to help with the gurgle.
We ran a test, by removing the 1 1/2" clean out plug. When flushing WC2,
the water in WC1 was nearly still. Think I need to tie in another vent.

But what ticks me is the old toilet had no issues.

Your drawing shows a drop with WC2 Lav2 Is this coming from a different floor? And is that vented out the roof? If it is coming from a different floor it is a stack and is not any type of vent for the lower fixtures on the lower floor. If you have no vent out the roof for fresh air. Your AAVS only suck in air they seal tight on the positive pressure thus the gurgling you are experiencing. On drawing 2 add a vent on the tub to air. Or vent the other lower bath to air.

 

[Yodaman]

Your drawing shows a drop with WC2 Lav2 Is this coming from a different floor? And is that vented out the roof?

Yes, WC2 and Lav2 are from 2nd floor half bath. It is vented straight up and thru the roof. (currently the only one)
Ok, your comment makes sense now.

Your AAVS only suck in air they seal tight on the positive pressure thus the gurgling you are experiencing.

I agree. I probably misspoke calling it a gurgle. We are actually experiencing a burp. A forced air burp. I got it reduced to a small single burp every 4th or 5th flush from WC2 by reducing the water level in tank WC2.

I found a opening in a HVAC chase to add another vent up and out the roof. But only enough room for a 1 1/2" . So I am considering tying into the 1 1/2 drain leg from LAV1 w/ AAV.

Performance wise, this should correct the belching. When we pulled the clean out plug at the end of that leg the pressure equalized with little movement in WC1 when WC2 was flushed.[/QUOTE]

On drawing 2 add a vent on the tub to air. Or vent the other lower bath to air.

Regarding the tub, no easy fix if main vent can not be considered as the usable vent.
I could tie it into the new 1 1/2 vent, ?

 

[Ghostmaker]

Then install the AAv on the tub 4 inches above the tub trap and vent the lav to air. One of the two must go to air to release your positive pressure that developed. An AAV will not do this.

 

[Yodaman]

Then install the AAv on the tub 4 inches above the tub trap and vent the lav to air. One of the two must go to air to release your positive pressure that developed. An AAV will not do this.

Lav to air vent is done and burp is gone. Plenty of room to add a AAV above the tub trap. Can do.
Thanks for your help.

 

[Ghostmaker]

Your welcome and thank you for listening...