Gray water and p-trap drain problem

[meant2shop]

We are currently camping at a full-service KOA. Today, before we left the RV for some sightseeing, I started a load of wash in our washer/dryer combo unit. When we returned this evening, there was standing "gray" water in the shower, which had overflowed onto the bathroom floor, carpet, and hardwood floor in front of the washer/dryer unit. There was also evidence that gray water had back halfway up the bathroom sink but had drained out at some point while we were gone. I had already done a load of wash yesterday, with no problem.

Hubby said, I'll go open the gray water "p-trap", which he did, and the standing water in the shower drained away.

We had a problem a couple of times before with standing water in the shower after showering, and it was corrected by opening the p-trap.

Hubby says the gray water p-trap has to be closed when I'm using the washer.

My questions are:
- Should the gray water p-trap be opened up and left open each time we arrive and hook up at a campground?
- does the p-trap have to be closed when I'm using the washer?
-what caused the gray water back up?
-after I sop up the water in the carpet with towels, how can I get rid of the mild "odor" from the gray water saturating the carpet? I've already sprayed the carpet with Febreze. Would shampooing the carpet, or scrubbing it with a product such as Resolve, help?

Thanks for your help,

Jim and Susan
2000 Fleetwood Pace Arrow Vision 36B
Merlin, OR (but currently in San Diego, CA for some sunshine)

[wimwega]

Our MH had the water from the washer/dryer and dishwasher backup into the shower as well. It was because the dump valve was closed and the grey water tank filled up. Now we leave that valve open all the time. Some instructions say to close the grey water valve so the black water tank hose can be flushed by the grey water dump. I am not sure what the P Trap has to do with the back up.
I hope this helps.

[steelheadbluesman]

Drain the gray tank before you run the washing machine, no more problem.

[RV Wizard]

You can have the grey tank valve open as there is only soapy water in this tank and no solids. Be sure that the vents for the grey water drains are good. Tank needs to be empty and not overfilled or the valve needs to be open. Good luck and keep us posted.

[paz]

Originally Posted by meant2shop

We are currently camping at a full-service KOA. Today, before we left the RV for some sightseeing, I started a load of wash in our washer/dryer combo unit. When we returned this evening, there was standing "gray" water in the shower, which had overflowed onto the bathroom floor, carpet, and hardwood floor in front of the washer/dryer unit. There was also evidence that gray water had back halfway up the bathroom sink but had drained out at some point while we were gone. I had already done a load of wash yesterday, with no problem.

Hubby said, I'll go open the gray water "p-trap", which he did, and the standing water in the shower drained away.

We had a problem a couple of times before with standing water in the shower after showering, and it was corrected by opening the p-trap.

Hubby says the gray water p-trap has to be closed when I'm using the washer.

My questions are:
- Should the gray water p-trap be opened up and left open each time we arrive and hook up at a campground?
- does the p-trap have to be closed when I'm using the washer?
-what caused the gray water back up?
-after I sop up the water in the carpet with towels, how can I get rid of the mild "odor" from the gray water saturating the carpet? I've already sprayed the carpet with Febreze. Would shampooing the carpet, or scrubbing it with a product such as Resolve, help?

Thanks for your help,

Jim and Susan
2000 Fleetwood Pace Arrow Vision 36B
Merlin, OR (but currently in San Diego, CA for some sunshine)

By p-trap, I'm assuming you mean the gray water dump valve. There are p-traps on all the drains to prevent odors from coming into the coach, but they are the same as the water-filled traps you have under the sink at home, and they can't be opened and closed.

The amount of water used by the washer plus what ever was already in the gray tank exceeded the capacity of the gray tank. The excess had no place to go, so it backed up into the shower, which is the lowest drain in the RV.

Different size loads and different cycles will use different quantities of water, but our Splendide combo usually uses around 12 gal. Extra rinse, pre-soak, larger loads, etc. will use more water. A ventless dryer will also use more water.

Some people like to leave the gray water drain valve closed so they can use the gray water to assist in rinsing the black tank when dumping. However, since the gray water is all liquid, we leave the gray valve open all the time when we have a sewer hookup specifically to avoid backups like you experienced. The black valve, however, should be left closed so the liquid won't drain away leaving the solids behind to create a major buildup.

To avoid black tank problems, especially since we always leave the gray valve open and don't have gray water available to assist rinsing the black tank, we make sure we use plenty of water when flushing the toilet to insure complete draining when I dump. I also pour several buckets of water down the toilet when dumping to help rinse the tank. We have done this for almost 6 years of full-timing, and have had no black tank problems. You could also add a black tank rinse if you don't already have one.

To get rid of the odor, I would do a thorough cleaning with a machine such as a Rug Doctor, then spray with Fabreeze after the carpet dries.

[Steve N Sal]

We leave our gray water valve open all the time when we're sitting at a site. The only time I close it is when the black tank gets 3/4 full. I'll let as much gray water accumulate in the tank until we dump the black and then use the gray for rinsing the hose. Now maybe twice a season with the gray dump valve closed I'll use a small bottle of Dawn dish soap and empty it's contents among our four traps and use as much hot water that we have( usually 10 gallons) and run that into the gray tank. We let it sit for a couple of hours add a little more water then dump the tank. The Dawn does wonders on breaking down any residue in the tank. Over time you'll get a build up from hair products, fabric softeners etc. but the dawn will desolve that and leaves you with a clean tank. At least that's been our experience.
Regarding your carpet you may want to use a wet/dry vac to suck up as much water as you can.

[docj]

We also have a washer/dryer and always leave the grey tank dump valve open to avoid the problems posted here. However, we recently experienced a clogged grey tank outlet pipe due to grease, food residue and washer lint that collected because the flow through the tank during normal use is not enough to flush these materials out. As a result I plan to periodically close the valve (every couple of weeks) and let the tank fill to assist in keeping it free of debris.

[jlfbatonrg]

We always keep the grey tank dump valve and have never had a problem. We wacth our tank level indicators, adn as long as we are less than 3/4 full the washnig cycle causes no problems. I have heard of similar issue where the vent pipe to the gray tank had slipped down or was installed improperly. The result was grey water backing up into the shower with very little water showing in the tank, and the water "burping" in the sewer lines. The theory is the water backed up because there was less pressure to overflow into the shower than to push the water out the vent pipe.

Another question. What is the size of your grey tank? It might be small enough that you have to empgty the tank before washing.

Jim