plumbing vents

[alisoncat]

Hi,

I'm having some trouble with the drains in a 1989 doublewide Fleetwood that we just bought. Poking around my plumbing and this forum I've found that all the sinks have the vents/checkvalves under the sink. There are two vents through the roof for each of the two bathrooms (sink and shower?). I have no idea how the washing machine vents. The drains are slow and they gurgle and will fill up and then suddenly release and drain. The washing machine is ok as far as we can tell, but even the toilets are affected somewhat.

As best I can make out, the roof stacks release sewer gas while the valves under the sinks admit air into the drain as the water flows down. Do I have that right? Is it reasonable that the problem could be caused by the checkvalves not working right? How are the toilets vented, do they tie into the pipes for the bathrooms out the roof? And what would I look for as far as the Washing machine goes?

A lot of questions, I know, but I'm trying to figure out how this system works! Any help is greatly appreciated!

Thanks,

Alison

[Greg]

Alison, you have it about right. The roof vents are usually for the toilets. the check valve type under the counters are for the sinks. A quick test for those is to simply unscrew them and see if the problem stops.

Washer drains may be a roof drain or it could have a check valve in the wall cavity above where the drain is.

If all of the drains are slow I would check for a main trap possibly under the home or even in the ground. If you are in a park try contacting them and see if there is a ground trap.

A quick way to see if it is in the home or in the ground is to disconnect the pipe from the ground and flush a toilet into a 5 gal. bucket under the pipe. If everything is normal, I would look towards the pipes in the ground. Greg

[alisoncat]

Thanks so much for the help! I finally got around to further investigation after a pause for some painting and electrical. Unscrewing the check valves helped some so I will be replacing them. I think some snaking might be in order too. Again, thank-you!