Successfully eliminated “P” trap under sink with Hepvo valve

YanniLazarus

this is my installation in aT@B320S 2020 model.   With the drain on the left of the sink it was hard to get a straight shot to the corner waste line to work.   Using a 1 1/2" threaded plastic nipple (black plastic) just below the sink drain kept everything as high as I could get it,  and the drain line is as short as possible.   Very happy! 

Dalehelman

You should have been able to connect the Hepvo directly to the bottom of the sink. There by gaining another 3 or 4 inches. 

YanniLazarus

I couldn't get that to work- my sink drain is closer to the corner than yours,  so your horizontal run came low enough on the stack to get the fittings to work.   I just dropped mine the 1 1/2 inches for the nipple.  My drain location made it harder. 

YanniLazarus

Hmmm. Plus the fittings. So you are right. Probably around 3 inches lost- but since my drain is closer to the corner,  overall not so bad. 

Dudlee

I was wondering if pulling the sink up and rotating it 180 to get the drain away from the corner would be worth it.  The install photo of jkjenn Looks like that’s what the crew did?

Dalehelman

Still looks good.

YanniLazarus

I think if I were smarter and used other fittings it might have worked a bit better.   The slip fittings I used required some minimum tubing lengths.  I do think keeping the horizontal run as short as possible is best (and laziness) kept me from exploring rotating the sink. 

ReenieG

@ReenieG, I agree with regard to the original pic you posted--there is no vent on the sink drain, and that suggests the Hepco valve itself does not require a vent to function properly.

Regardless, the grey tank itself must still be vented to prevent pressure from impeding drainage. I assume in your pic (which is not a T@B) the grey tank is probably vented in another location that is more convenient for the layout of that particular camper.

If you go look at your 320 I'll bet a nickel it looks like the pictures Dalehelman posted with the vent in place.

@ScottG Yes, I have no doubt the pic I took which Dalehelman circled is MY undersink piping. I guess my "confusion" is that in that pic I posted of my T@B where Dalehelman circled, I don't see a vent. I will have to actually LOOK and see for myself I suppose, lol. 

VictoriaP

ReenieG said:

@ReenieG, I agree with regard to the original pic you posted--there is no vent on the sink drain, and that suggests the Hepco valve itself does not require a vent to function properly.

Regardless, the grey tank itself must still be vented to prevent pressure from impeding drainage. I assume in your pic (which is not a T@B) the grey tank is probably vented in another location that is more convenient for the layout of that particular camper.

If you go look at your 320 I'll bet a nickel it looks like the pictures Dalehelman posted with the vent in place.

@ScottG Yes, I have no doubt the pic I took which Dalehelman circled is MY undersink piping. I guess my "confusion" is that in that pic I posted of my T@B where Dalehelman circled, I don't see a vent. I will have to actually LOOK and see for myself I suppose, lol. 

@reenieG The circled area in that pic IS part of the vent stack, the 90° elbow above where the sink drain attaches to the vertical pipe leads to the horizontal pipe behind the toilet and exits (vents) out the driver’s side of the trailer. 

Kr@cken

Another newbie question. What would I want to replace my P trap. Is this something that is recommended?

Sharon_is_SAM

It is done to free up space under the sink as the “p” hangs down lower and the Hepvo can be mounted parallel to the floor.  What kind of trap do you have under your sink in the 2020 Boondock?

Travelin3D

I just did this mod in June on my 2020 320 BDL. Here’s a before and after.

GatorEgg

Nice.  But the ptrap keeps my Keurig kcup secure in there. 😬

TXMacDad

Our sink mod in 2014 T@B 

rcarlson1957

Finished mine yesterday. 

Denny16

Looking good...  
cheers

ReenieG

I finally did mine. There was alot of buildup in the p-trap, probably from water evaporation when storing. Just hoping this all doesn't leak! I'm always leery of plumbing fittings when I glue them together, although it's more me than them.

I'm planning on replacing the faucet with a mod I saw from Facebook (link to faucet) and possibly replacing the sink, (link to sink) since it would prob still be doable. (sink is reportedly 1" deeper) Since I used a flex drain fitting I may still be able to mod the sink, although I'm still considering the microwave install under the sink which I think might be sink OR microwave, not both. We'll see after the faucet install.

ReenieG

@Dalehelman @LittleBoyBlue I like your mod appearances better than mine. Not sure why mine looks slanted in the final pic. Hmmm... It looks like your mod might have been easier to do with those white connections. If mine leaks, I'm copying yours, lol.