Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 06-06-2013, 03:48 PM   #1
Senior Member
 
Bryan H's Avatar
 
Join Date: Jun 2012
Posts: 143
Should an anti-siphon valve do this?

Ok, a little background first. We recently bought a 2008 Winnebago Destination 39W. Since our purchase, we have always noticed a tank odor when the coach is closed up for a day or two. In an attempt to remedy this problem, we flushed all the tanks thoroughly, and then we added tank powder to the kitchen sink in order to 'sanitize' that grey tank. As we were adding water, the flow from the faucet was more than what the drain could handle, so the sink began filling up. Once that happened, water began gushing out from the piping under the sink. After cleaning up the mess, I noticed there is an anti-siphon valve downstream of the p-trap. The elevation of the valve is right at the bottom of the sink. So basically, as soon as the water reaches a depth of 1" or so in the sink, it starts coming out the valve. So, my question is, is the anti-siphon valve faulty? I have no idea how they are designed, so I'm not sure if they should overflow in this type of situation.

Any thoughts are appreciated.

Bryan
__________________

__________________
2015 Thor Outlaw 29H Class C Toyhauler
2015 Jeep Wrangler JKU Toad
Bryan H is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 06-06-2013, 04:45 PM   #2
Senior Member
 
ChasA's Avatar
 
Join Date: Mar 2007
Location: Apex, NC
Posts: 1,857
The valve is not your problem right now. You have a blockage between the sink drain and the gray tank. I'd run a small plumber's snake down the drain to see if you can break whatever is. Probably kitchen grease.
__________________

__________________
2010 Winnebago Journey Express 34Y
2010 Freightliner XCS (mfd 9/'09)
'07 Saturn Vue V6
ChasA is offline   Reply With Quote
Old 06-06-2013, 04:56 PM   #3
Senior Member
 
Bryan H's Avatar
 
Join Date: Jun 2012
Posts: 143
Agreed, there's definitely a blockage of some sort, otherwise the sink would not fill up.

But that raises a question. How does the anti-siphon device keep tank gas from escaping? It's between the trap and tank, so the trap doesn't help. What keeps tank odors from wafting out of it?
__________________
2015 Thor Outlaw 29H Class C Toyhauler
2015 Jeep Wrangler JKU Toad
Bryan H is offline   Reply With Quote
Old 06-06-2013, 04:56 PM   #4
Senior Member
 
UFO Pilot's Avatar
 
Winnebago Owners Club
Workhorse Chassis Owner
Join Date: Aug 2007
Location: Sonoma County, CA
Posts: 4,612
My 39W doesn't act that way so I assume you have a blockage. The galley sink drain is very long as it goes thru the slide and under the bed. The hose under the bed may be kinked? You have to remove the mattress and then remove 4 or 5 screws to lift the bed "cover" up. If you do access under the bed, be sure and check the framework that the bed slides over. The screws in mine had all pulled out and the bed was binding when the slide moved in or out.
__________________
Wayne & Roberta and Maggie the Miracle Dog
08 Winnebago Destination 39W Gas UFO Workhorse Chassis
Making the Journey in our Destination

UFO Pilot is online now   Reply With Quote
Old 06-06-2013, 05:05 PM   #5
Moderator Emeritus
 
Gary RVRoamer's Avatar


 
Join Date: Jan 2000
Location: Silver Springs, FL. USA
Posts: 18,085
An anti-siphon valve is simply a check vale that passes air rather than the more familiar water check valve. It's formal name in plumbing is actually an "air admittance valve". It allows air to pass inward and prevents air (or liquids) from passing outward. Basically it is just a rubber flapper that moves in only one direction - inward.

Since yours is allowing both fumes and liquid to leak out, if is clearly defective. They are simple to replace - any home center or plumbing supply will have them and RVs use standard 1.5" air admittance valves. They are not glued to the pipe - just a friction fit.

However, as others have said, your main problem is a blockage in the sink drain line.
__________________
Gary Brinck
Former owner of 2004 American Tradition
Home is in the Ocala Nat'l Forest near Ocala, FL
Summers in Black Mountain, NC
Gary RVRoamer is offline   Reply With Quote
Old 06-06-2013, 05:18 PM   #6
Senior Member
 
Bryan H's Avatar
 
Join Date: Jun 2012
Posts: 143
Is it possible that this valve, if defective, could be causing the odor AND slow drain problem? If it's not opening properly to allow a large volume of water through, I'm wondering if that could cause the backup. At times, the drain seems to work fine.
__________________
2015 Thor Outlaw 29H Class C Toyhauler
2015 Jeep Wrangler JKU Toad
Bryan H is offline   Reply With Quote
Old 06-06-2013, 09:02 PM   #7
Senior Member
 
mfire1339's Avatar


 
Monaco Owners Club
Workhorse Chassis Owner
Join Date: Jun 2008
Location: Glendora Ca.
Posts: 1,344
Bryan,

The valve only deals with air. Not water. It is a result of a drain problem and is easy to change.



Mike
__________________
2004 Monaco Monarch
Blueox, SMI, 1990 Wrangler YJ
mfire1339 is offline   Reply With Quote
Old 06-08-2013, 01:14 AM   #8
Senior Member
 
chboone's Avatar


 
National RV Owners Club
Ford Super Duty Owner
Join Date: Sep 2010
Location: Horse Town USA, CA.
Posts: 2,933
If the "air admittance valve" sticks closed it can cause the drain to backup because it is not allowing air into the drain for the water to flow. A friend of ours had the same problem with her 2008 Monaco, replaced the air admittance valves cured the problem. If your is the style that has a light spring in it, they were discontinued because of problems with them sticking closed. Replace your valve(s) and you should not have anymore problems.

Chuck
__________________
1999 35 ft. Dolphin 5350,F53 Chassis Chassis build date 1/99, Banks System, 5 Stars Tune, Air Lift Air Bags front & rear, Koni Shocks,Blue OX TruCenter,TigerTrak track bars front & rear, Roadmaster 1-3/4" rear auxiliary sway bar,2004 F450 Lariat 6.0 Diesel Crew Cab DRW with B & W Custom Truck Bed, 1994 36 ft. Avion 5th Wheel
chboone is offline   Reply With Quote
Old 06-09-2013, 09:10 AM   #9
Senior Member
 
bobmac's Avatar
 
Winnebago Owners Club
Freightliner Owners Club
Join Date: Mar 2008
Location: Southern Ontario
Posts: 926
The fitting is really a "vent" designed for use when a proper vent to the roof to cannot be installed. It allows air in to the drain line as others have stated. It is equipped with a spring loaded shut-off to prevent backflow and the overflow of liquids if the drain is blocked. These are cheap fittings and should be available at an RV supply or Home Depot. Over time, the backflow prevention can clog up and fail as yours appear to have done. Best solution is to replace it once you have cleared the blockage that is restricting the drain. There are likely others installed under other sinks that you might want to check as well.
The odor could very well be the result of the evaporation of liquid in the P-traps - you need to run a bit of water into the traps periodically when the coach is stored. Otherwise, once evaporated, there is a direct path from the tank into your coach for odors to escape.
__________________
Bob
09 Journey 39Z
Southern Ontario
bobmac is online now   Reply With Quote
Old 06-09-2013, 11:26 AM   #10
Moderator Emeritus
 
Gary RVRoamer's Avatar


 
Join Date: Jan 2000
Location: Silver Springs, FL. USA
Posts: 18,085
If the air-admittance valve sticks closed, the only effect should be water getting sucked from the nearby sink P-trap with a lot of glug-glug-glug noise. The main roof vent will still provide enough air relief to avoid a back-up.
__________________
Gary Brinck
Former owner of 2004 American Tradition
Home is in the Ocala Nat'l Forest near Ocala, FL
Summers in Black Mountain, NC
Gary RVRoamer is offline   Reply With Quote
Old 06-09-2013, 06:18 PM   #11
Senior Member
 
Selah's Avatar
 
Join Date: Oct 2012
Location: Indiana
Posts: 2,319
It is the valve, probably installed backwards. Take it off and check the direction of flow through the valve. Flow should be IN only. If it has been installed backwards it would then allow air to flow Out of the gray tank instead of the other way around causing your Oder problem. Check that first.
__________________
Paul, Kathy, and Tux the Mini Schnauzer
2014 Tiffin Phaeton 42 LH, 2013 Honda CRV
"When the time comes to look back, make sure you'll like what you see"
Selah is online now   Reply With Quote
Old 06-09-2013, 07:14 PM   #12
Senior Member
 
jeepfreak's Avatar
 
Join Date: Mar 2003
Location: Home is where we park it
Posts: 417
Oatey 1-1/2 in. ABS PTC In-Line Cheater Vent-39012 at The Home Depot
__________________
2007 Allegro 34wa .WH w20 8.1 6speed. Bow tie powered 79 CJ7 or a 2014 Jeep Unlimited Rubicon Toad.
jeepfreak is offline   Reply With Quote
Old 06-10-2013, 12:26 AM   #13
Senior Member
 
chboone's Avatar


 
National RV Owners Club
Ford Super Duty Owner
Join Date: Sep 2010
Location: Horse Town USA, CA.
Posts: 2,933
On our friends 08 Monaco The only roof vent was directly connected to the gray tank. All of the sinks and shower had the air admittance valves a total of four, when they would stick closed which ever fixture it served would not drain or suck the water from the other P-traps. As soon as the valve was removed the fixture would drain.

Chuck
__________________
1999 35 ft. Dolphin 5350,F53 Chassis Chassis build date 1/99, Banks System, 5 Stars Tune, Air Lift Air Bags front & rear, Koni Shocks,Blue OX TruCenter,TigerTrak track bars front & rear, Roadmaster 1-3/4" rear auxiliary sway bar,2004 F450 Lariat 6.0 Diesel Crew Cab DRW with B & W Custom Truck Bed, 1994 36 ft. Avion 5th Wheel
chboone is offline   Reply With Quote
Old 06-10-2013, 06:32 AM   #14
Community Moderator
 
"007"'s Avatar


 
Nor'easters Club
Workhorse Chassis Owner
iRV2 No Limits Club
Join Date: Oct 2004
Posts: 26,786
The vent under sink should be higher than the P trap to work correctly.
The power maybe whats causing the blockage and didn't go down into gray tank.
Use bleach to sanitize the gray tank will make a good cleaning.
__________________

__________________
98KSCA, 99MACA, 03 KSCA-3740- 8.1 Chev-- ALLISON Trans, now in good hands
VISIT the NEWMAR QUICK TIPS & EASYMODS 1 & 2
QUICK TIPS # 3
RV SYSTEMS & APPLIANCES & RECALLS --- TECH INFORMATION
"007" is online now   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 07:08 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.