Author Topic: Slow sink drain  (Read 5121 times)

Kurt Schroeder

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Slow sink drain
« on: April 19, 2015, 12:07:36 AM »
After reading all the past associated threads, I'm thinking my problem could be a sticking vent valve. Past thread indicated a vent valve under each bathroom sink, but was unsure if the kitchen sink had one or shared one. The kitchen sink is my current problem, and I've verified the flex hose is not damaged and that the standard "plumber's helper" does not free it. Can anyone provide additional information if and where the kitchen sink vent valve can be found? Also can they be cleaned/lubricated or is the only option replacement? Thanks for any help provided. As usual, these problems only occur on the road, on a weekend.

Lee Welbanks

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Re: Slow sink drain
« Reply #1 on: April 19, 2015, 12:39:19 AM »
Kurt,

Look under your sink and where the drain has the two sinks connected there should be a Tee with a riser with a fitting in the top end threaded into the riser, that will be the vent/check valve. It should un-screw, take it out and then run some water down your sink to see how it drains. If it drains faster then the vent valve is probably stuck.
On my PT if we don't have the strainer plug down in the other little sink it will drain faster.

Kurt Schroeder

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Re: Slow sink drain
« Reply #2 on: April 19, 2015, 08:51:36 PM »
Lee:

Thanks for the reply. I have the installation you describe on both the bathroom sinks which operate normally, but the double kitchen sink does not have a similar valve, at least as far as when the drain line disappears behind the cabinets (well after the two traps). There was plenty of room to install a valve, yet
Beaver chose not to. If a valve is necessary, surely they wouldn't have put it in a inaccessible area under the stove or behind the washer/dryer, would they?  We have the stationary kitchen island, which prevents the removal of the adjacent large drawers to view the line as in passes under the stove. There may be a way to fool the slide hardware to release the drawer before full extension, but I haven't figured it out. Surely they wouldn't produce a design that precluded removing the drawers...would they?

I'm losing faith that the valves are causing the problem. Starting with a fully clogged drain, extensive use of a plunger only improved it slightly, but last night I put in drain cleaner (approved for all drains) and after sitting overnight there was a significant improvement. As all buyers of used coaches, we can only speculate what the previous owner might have been putting down the drain.

Kurt

Kurt

Fred Brooks

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Re: Slow sink drain
« Reply #3 on: April 19, 2015, 09:07:40 PM »
     Hi Kurt,
 By the nature of coaches that have flexable drain hoses, it is not an idea design. They have the ability to lay flat or even go up hill. Its amaziing how they can accumulate layers of kitchen sink grease after 10 years of use. I believe your on to it using the drain cleaner. The most effective repair would be to disconnect the flex hose and run a brush snake thru it. Not for the weak hearted cause it is a nasty job.
     Regards, Fred
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Joel Ashley

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Re: Slow sink drain
« Reply #4 on: April 19, 2015, 09:39:36 PM »
If the kitchen sink is in a slide, the flex hose can develop a kink in it that can restrict flow, especially in one slideout position.  Did you notice if the plugged condition was worse when the slide was open or closed?  A kink in that flex hose created a big problem for me when the crimped spot caused the hose to split in the crimp's corners and, unbeknownst to us, leak drain water under the tile flooring.  Installers had cut the flex hose a few inches too short so that in the slide's out position the hose kinked at its lower pipe attachment rather than gently bend along its length, similar to a garden hose you fold back on itself;  the longer the loop, the less likely the hose is to kink.

On ours, access to the flex hose assembly is via a removeable panel, on the aisle-side wall next to a pull-out "pantry" below the stove, that has hidden cabinet catches top and bottom, and that just pulls straight out by placing your fingertips behind its edges.

As to the vents, my coach doesn't have one for the kitchen or shower, but the two mid-coach bath sinks have the valves, and I think also the washer/dryer drain.  They apparently are supposed to be enough, together with a tank roof vent, to prevent the traps from being sucked dry when you empty your gray tank.  I'm not sure it works, since my ventless shower drain reeks after tank emptying and I have to add a couple cups of water to fill the shower trap to stop the odor.  I should try to remember to put something over the shower drain before dumping tanks to limit trap evacuation I guess.

For whatever reason the kitchen sink trap doesn't seem to display that issue;  perhaps it commonly gets used before tank fumes back up that pipe.  Each trap in the coach should have been installed with an associated vent valve, I agree.

Joel
« Last Edit: April 19, 2015, 09:50:54 PM by Joel Ashley »
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Lee Welbanks

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Re: Slow sink drain
« Reply #5 on: April 19, 2015, 10:37:33 PM »
Lee:

Thanks for the reply. I have the installation you describe on both the bathroom sinks which operate normally, but the double kitchen sink does not have a similar valve, at least as far as when the drain line disappears behind the cabinets (well after the two traps). There was plenty of room to install a valve, yet
Beaver chose not to. If a valve is necessary, surely they wouldn't have put it in a inaccessible area under the stove or behind the washer/dryer, would they?  We have the stationary kitchen island, which prevents the removal of the adjacent large drawers to view the line as in passes under the stove. There may be a way to fool the slide hardware to release the drawer before full extension, but I haven't figured it out. Surely they wouldn't produce a design that precluded removing the drawers...would they?

I'm losing faith that the valves are causing the problem. Starting with a fully clogged drain, extensive use of a plunger only improved it slightly, but last night I put in drain cleaner (approved for all drains) and after sitting overnight there was a significant improvement. As all buyers of used coaches, we can only speculate what the previous owner might have been putting down the drain.

Kurt

Kurt

I also have the island in my PT and the slide has to be all the way out to get the drawers out, I will have to look at mine to see if it does have a vent valve. I do know the sinks drains far better if the other sink stopper is not down.
I think Fred is spot on with running a brush snake through the line to clean her out once and for all.