Where the bathroom odor comes from

Welcome back to Happi Plumbing Channel. We will talk about how to diagnose where the bathroom odor comes from.

The customer was bothered by the persistent odor in the bathroom.

Background Introduction:
The client lives in a house built in recent years, which has a total of 5.5 bathrooms.
There is 1.5 bathrooms on the first floor and 4 full bathrooms on the second floor.
One of the kids’ bathrooms on the second floor has had a persistent odor issue, which seriously affects their daily life and their children’s health. The client suspects that the odor might be coming from the toilet.

Toilet Flush Test:
During testing, we flushed the toilet and observed that the bathtub emitted a loud gurgling sound. Our initial assessment suggests that there is an issue with the toilet’s venting system, which causes a siphon effect each time the toilet is flushed.
This siphoning pulls the water out of the tub drain P-trap, breaking the water seal and allowing sewer gas to escape into the bathroom.

Attic Inspection:
We entered the attic to examine the venting system for this bathroom.

Findings:
We discovered that this bathroom does not have a VTR (Vent Through Roof), nor is it connected to any other bathroom’s venting system.

Sink Cabinet Inspection:
Upon opening the cabinet under the bathroom sink, we found a 1-1/2 inch Studor vent (air admittance valve).
It appears that the entire bathroom is relying solely on this single vent, which was extremely surprising.
This type of design is non-compliant with plumbing codes, and raises the question of how such a system was both designed and passed inspection.

如何诊断洗手间异味来自哪里？

客户问题：洗手间一直有异味

1. 客户概况，这个客户是一个这几年新建的房子，有5个半 一楼有1个半，二楼有4个，二楼的一个kids bathroom一直有异味，严重影响到生活和孩子的健康，怀疑异味来自马桶
2. 测试马桶冲洗，发现冲马桶的时候tub 发出很大的咕噜咕噜声。初步判断是马桶的vent 系统有问题，导致每次冲洗马桶，产生虹吸siphon, 把tub drain p trap 里的存水都吸走了，导致p trap 的水封失效，sewer gas came out.
3. 进入attic ，检查这个bathroom的vent 系统
4. 发现这个bathroom没有VTR (vent to roof) ,也没有vent 连接到其他bathroom vent
5. 打开bathroom sink cabinet， 发现一个1-1/2 inch studor vent, 这个整个bathroom应该是只靠这一个 这让我无比惊讶，这种设计不合规，是如何设计出来的，又是如何通过inspection的？