Sewer smell in trailer and under kitchen sink

We took one too many flushes into our black tank last week. got the same smell into the trailer as when the septic pumper comes to visit at home. From the toilet seal it looks like you have a little more room, but the vent stack must stick down into the tank a bit, so less volume than it appears.

Nasty surprise if you're not ready to dump and hit the road...only one visit to the campground facilities needed. Should have dumped the 1/2 day of travel and dry camping "deposits" when I got into the 3 night campground. Oops.

Ralph

Ha! Just had the same happen to me. Our trailer is permanently parked in a campground so we don't have the option of sloshing around a cleaner inside the tank - but - then again - the smell wasn't coming from the black water tank - it was under the sink.

So... I thought back to when we first opened the trailer this Spring and the couple of times we had already been there - no smell - except the last time we were there the kitchen sink didn't drain well so I plugged one side with the palm of my hand and 'plunged' the other side of the sink with my other hand until the water drained through.

Next time we came up to the campground I swore something had died inside the trailer - and - more specifically - it seemed to have died under the sink inside the cabinets somewhere.... ugh!

We normally have only the drain for the grey water tank 'open' (we are on a sewered lot) so I closed up the drain - added about 5 minutes of water flow to the tank - added liquid laundry soap, calagon water softener, liquid fabric softener and let it set overnight. Next day I drained the tank, brought in the hose and flushed, flushed, flushed both drains in the kitchen sink. Ta da! No more smell! :)

Thanks all for your responses. We are going to check out the air admittance valve and see if that's what may be causing the problem. We always put plenty of water in with the drop in packets and also do a thorough cleaning of the tank when we get home with a long wand attached to the hose. This gets alot of the toilet paper out, which holds smell too. Also may try other things to control the odor rather than the drop in treatments. Have read in other blogs on this site about using laundry detergent along with calgon as well as lots of recommendations on the Happy Camper brand. Again, thanks for your responses and happy camping everyone!

Most don't realize that the gray tank can smell something awful also. As mentioned, you4 problem is probably the AAV and needs to be replaced.

However, I have to jump in here with my usual rant on chemicals. In my, and many others, opinion....chemicals just aren't needed. If you have an odor, you have a problem with a leak, broken seal, plugged vent pipe, or in this case, a faulty AAV. Chemicals just "mask" the odor and does nothing to repair the problem.

The key is water! Before traveling, rinse out the tank the best your can and then put in a couple of gallons of water and add a cup of laundry soap (I use liquid Oxy-Clean) and a capfull of liquid Calgon water softener. During the traveling the sloshing solution will wash down the inside of the tank and the water softener will coat it with a slick film that is resistant to "stuff" sticking to it. Once at your destination, drain and rinse the tank once more and add a couple of gallons of water back into the tank. Never, never leave the tank without water in it.

You can do the same with the gray tank, except since they don't have a rinse system, you have to make do without it.

Do the same procedure again when you head home and rinse once you are.

I've had many different rv's, from pop-up to my current motor home and have always used the same procedure. My tanks do not smell in the rv and my tank level gauges work perfectly

Anyway, that's my story and I'm sticking to it.

Ron

wildtoad wrote:
See if there is a pipe with a round vent cap under the kitchen sink. If there is this is a vacuum breaker and could have gone bad. They are available at lowes or other stores.

Air Admittance Valve.....
Installed on a stub pipe on kitchen sink drain line after 'P' trap
Allows air into that section of drain line when draining waste tank.
Keeps 'P' trap from getting sucked dry

(could be one on bathroom sink drain line also)





Just hand screwed into stub pipe

GmaTessa wrote:
We have a new to us (2014) travel trailer and have had it out 3 times so far this year. It's a smaller trailer (22 ft.) and therefore has a small black water holding tank (I believe 26 gallon). We are usually out for 6 days and use a portable waste tank to dump after 3 days. Afterwards, we notice a distinct sewer smell in the trailer, and seems to be worse when we open the cabinet doors under the kitchen sink. NOTE: There is no smell in the bathroom and we use drop in tank treatments when we first set up on arrival at the campground and again after dumping mid-trip. We have been on trips in April when weather was cooler and in May and June when it's been hotter so thinking weather is not a factor. Anyone have a clue what might be causing the smell to come into the trailer and under the sink?

You mean other than what you put in it? Frequent flushing, adding treatment, and dumping may help.

Volume of water is the key. Start at 1/2 full, add treatment, and get back to us.

See if there is a pipe with a round vent cap under the kitchen sink. If there is this is a vacuum breaker and could have gone bad. They are available at lowes or other stores.