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310RL - Sewer smell from bathroom sink when water turned on

bhidalgo

bhidalgo

Well-known member
Just started happening last week. When I turn bathroom sink faucet I get a bad sewer smell for some reason. Does not matter if grey tanks are full or not. Or if vent fans are on or open

Living out of RV part-time now, so all three tanks are dumped weekly.
I put "RV Digest-It" down all four drains as well after tanks are dumped.

Fresh water tank was dumped a few months, and I only put about 30 gallons of fresh water in it afterwards. Rarely use water in boondocking mode anymore.

Have a 2-stage fresh water filter along with a whole-rig water softener that connects RV Park water to Nautilus fresh-water inlet connector.

Have been in current RV park roughly 2 months now.

Any ideas how to address issue?

Thanks...Bill
 
BryanValRox

BryanValRox

Well-known member
bhidalgo said:
Just started happening last week. When I turn bathroom sink faucet I get a bad sewer smell for some reason. Does not matter if grey tanks are full or not. Or if vent fans are on or open

Living out of RV part-time now, so all three tanks are dumped weekly.
I put "RV Digest-It" down all four drains as well after tanks are dumped.

Fresh water tank was dumped a few months, and I only put about 30 gallons of fresh water in it afterwards. Rarely use water in boondocking mode anymore.

Have a 2-stage fresh water filter along with a whole-rig water softener that connects RV Park water to Nautilus fresh-water inlet connector.

Have been in current RV park roughly 2 months now.

Any ideas how to address issue?

Thanks...Bill
Click to expand...
Bill, not sure if you are aware of this document or not, but it might help you out some.
 
bhidalgo

bhidalgo

Well-known member
Thanks Bryan.

Jim - I looked under sink this morning and there is both a P-trap and a Backflow preventer.
Sink used several times a day so there's water in p-trap. I did not see any leaks under sink to make me think otherwise.

Guessing I am going to have to get another Backflow Preventer [edited to delete p-trap entry] and replace it.

Thanks.
 
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L

Lantley

Well-known member
If the trap has water in it and there are no leaks it is not the source of the smell.
I would then focus on the backflow preventer. Does it leak?
I'm assuming the back flow preventer is connected to your black tank flush. Have you tried to use Black tank flush? Does it leak or smell flush is used. Does it smell when toilet is flushed?
 
BryanValRox

BryanValRox

Well-known member
Bill, I would agree with Lantley’s statement. The p trap is just a water trap, so as long as it holds water, gases /smells can’t reverse direction into the living area.
My gut is also telling me it isn’t the back flow preventer, as at least in my mind, black and gray are two separate systems, isolated from one another.
My money is on an air emtenance valve under the sink if there is one or the shower in-line membrane style trap. I am not a betting man, but would place money on the in-line membrane trap for the shower. Hair could be lodge or stuck in it holding it open allowing the smell to come up the shower drain. The constant exposure to soap, shampoo, could have also resulted in a less than flexible membrane cause gases to come up thru the shower drain.
Please keep us posted!
 
R

rick 6621

Well-known member
Hi Bill, take one step at a time, first put a bag around air admittance valve, this will eliminate any gas leaking from valve, wait a day if smell is still there then remove inline trap from shower and clean again wait a day if smell persist, the PO which is made of plastic has deteriorated and must be replaced.
 
bhidalgo

bhidalgo

Well-known member
Thanks all. Really do appreciate the responses and suggestions so far.
I type too fast sometimes and don't always spell check enough ... I meant to say earlier that it looks like Backflow Preventer may need replaced.
But will hold fast on that until I do more investigating.

Here is what I know for sure so far:
  • First started noticing smell from sink area about 2 weeks ago.
  • No obvious or observed leaks from under sink area.
  • Do not notice any sewer-type smells from shower when using shower. BUT, will take a good sniff later when taking shower tonight.
  • Just dumped all tanks this afternoon and no unusual odors other than what I have smelled since we first dumped tanks 3 years ago.
  • Sink seems to be the area with the smell during/after running water from sink faucet.
I'll take it one suggestion at a time and investigate thoroughly before I go ripping stuff out and spending money I don't need to spend. And end up with a load of spare parts.

Gotta love DIY....
 
Grassjohn

Grassjohn

Well-known member
Here’s another reference document:

After a few frustrating months in our 2021 Paradigm 385FL, our smell was due to item #1. It’s easy to check; remove the vent cap and observe if the vent pipe is long enough. The problem was hard to pinpoint (I bought new air admittance valves) and running the AC made it happen more often, sucking the “bad” air out of the attic.
 
L

Lantley

Well-known member
Good idea. Check roof vent while you are at it.
I've experienced smells due to roof vent on another brand RV. The vent cap on my roof was missing which created the problem.
 
F

Fishfnatic

Well-known member
I get sewer smell in my 310 rl when using max air vents. I try not to use vents too much. I posted about this couple months ago and just deal with it. I add treatments to all tanks and seems to help. It is intermittent. My roof vent caps seem fine but who knows. I looked at vent under sink and when I have to change out will probably have to lift sink out of counter as there is not room to change out the way plumbing is under sink.
 
T

Tigger2

Member
@Fishfnatic Attaching pics of the issue for us. But this is just a part of a much much larger stinky problem that goes back to QC at the factory. Bottom line, go on the roof, gently remove the vents (they come off, but may take a little effort), and check the roof membrane. Ours was cut in a half moon, not removed, and just left to flap back down over the pipe. Thus, no air can escape. The smell is so disgusting! IN ADDITION!! ...my husband found... one of the "holes" was missing over 2 feet of pipe!!! He replaced it himself (yes we are still under warranty) but we later found even more serious "plumbing" issues. Start here and see if it helps.
 

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CiscoRaccoon

CiscoRaccoon

Well-known member
I know this is a very old thread. Going back to the original complaint the smell comes from the faucets (kitchen, bathroom, shower), and only when running hot water. I have a 310 and has happened several times. In March, I used bleach mixture and went thru a winterize process so all piping had bleach in it. Let it sit for 8 hours. Flushed system, smell gone. Here is is July and odor is back ONLY when running hot water. We are leaving for a 7--8 week trip so need to find a solution. It's not:
  1. Vent piping
  2. toilet seal leaking
  3. Bathroom sink trap not full (smell is hot water, shower, Kitchen, sinks)
  4. Anode rod rotting (I was told cheap rods have done this - I pulled it in Feb, smell is back)
  5. Power exhausts are off
Any new ideas? I will have to flush again with bleach (only hot water side) I drain the hot water tank, turn valves to winterize (except leave red turned upwards so it fills the 12 gallon hot water tank. So weird and so unsanitary. Thanks!
 
CiscoRaccoon

CiscoRaccoon

Well-known member
Grassjohn said:
Here’s another reference document:

After a few frustrating months in our 2021 Paradigm 385FL, our smell was due to item #1. It’s easy to check; remove the vent cap and observe if the vent pipe is long enough. The problem was hard to pinpoint (I bought new air admittance valves) and running the AC made it happen more often, sucking the “bad” air out of the attic.
Click to expand...
Hey Grassjohn, could you resend that link, it says expired, thanks in advance.....
 
CiscoRaccoon

CiscoRaccoon

Well-known member
Lantley said:
Are you on well water Or chlorinated city water?
Click to expand...
City water, not sulfur related if that's where you are going. Last week we ended 11 days on Lake Superior and smell began - no neighbors had an issue, but several came and smelled and agreed, it stunk. Thanks for reaching out.
 
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