Location of anti-siphon check valves?

Lost_my_beer

Active Member
I can’t find my forward black tank anti-siphon valve for the life of me. It is not under the bathroom sink. It is not seen via the shower access panel. I can’t find it behind the outside water panel. The rear one was in the aft lav under the sink as expected.
Has anyone with a Cyclone 4270 or similar found it? Possible that it was not installed? Or maybe both are plumbed together?
No, I’m not going to drop all cloraplast to hunt for it! Not leaking…yet, but would love to know where it is preemtively!
Thanks,
Troy
 

jmarnell

Well-known member
In our Cyclone it is behind the access panel in the shower. But it was tucked off to the side so I had to look with a flashlight to find it.
 

Lost_my_beer

Active Member
Hmmm. I used a light and mirror and could not find it. Assumed it would be there.
Was it to the left or right? I might have to use a coat hanger and do some fishin maybe…
Thanks!
Troy
 

Garypowell

Well-known member
Sometimes it is easier to spot the lines from the basement as they go up into the wall. At least on mine there were 4 pex lines going up the hole. I determined one was hot and one was cold by running the shower.
Then verified the other two were for the anti siphone lines by running water through the flush system.

not sure of your goal but mine was to cut the lines and join them together to take the anti siphon out of the circuit. I think the original lines are still up in the wall.
 

jmarnell

Well-known member
Hmmm. I used a light and mirror and could not find it. Assumed it would be there.
Was it to the left or right? I might have to use a coat hanger and do some fishin maybe…
Thanks!
Troy
Mine was just to the right of the access hole. But it sounds like yours isn't there as while a little to the right, it wasn't that far. Once I spotted it I could reach in and grab it with my hand.
 

Lost_my_beer

Active Member
Thanks Gary and John.
I will look again in the shower before I dig into the basement again and look there. Great idea to determine which line by running water! Never thought if that.
Troy
 

Gary521

Well-known member
I can’t find my forward black tank anti-siphon valve for the life of me. It is not under the bathroom sink. It is not seen via the shower access panel. I can’t find it behind the outside water panel. The rear one was in the aft lav under the sink as expected.
Has anyone with a Cyclone 4270 or similar found it? Possible that it was not installed? Or maybe both are plumbed together?
No, I’m not going to drop all cloraplast to hunt for it! Not leaking…yet, but would love to know where it is preemtively!
Thanks,
Troy
Don't bother looking for it. A lot of us, me included, have bypassed this device altogether. Mine has not worked from day one. I bypassed this in a former trailer too. Just find the line coming from the black tank.
 

sengli

Well-known member
On our last three heartland fifth wheels it was in the wall of the shower, where the controls were. Also I could easily find them from underneath in the basement. Gary said it, the lines go up thru the ceiling of the basement area in a grouping. I second the idea of by-passing the anti siphon, as the first two leaked badly on first use.
 

Lost_my_beer

Active Member
Perfect. I will look this weekend. Yea, bypassing is the plan.
Thanks again,
Troy
pic is my aft lav finished…
 

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mwc

Active Member
Mine in my cyclone was in the dresser in the front bedroom, no kidding. Left side behind a drawer. Glad when it blew it was on my wife side of the dresser. Who puts that thing in there knowing they blow all the time. I bypassed as well.
 

SLO

Well-known member
Anti-siphon valves can be a real pain but they are a health/safety item. They are placed above the flood rim of the fixture they are protecting. In the case of our RVs, above the rim of the highest toilet/toilets attached the black tank. That’s why they’re placed in high, inaccessible places. If you placed the anti-siphon valve below the flood rim you wouldn’t have to worry about siphon because the black tank could just gravity flow back into the supply line. Same reason why most of us have an airgap (anti-siphon valve) on our dishwasher at home.

A solution to just removing the anti-siphon valve and connecting the lines directly would be to install a spring loaded check valve in it’s place. They would be completely sealed and not opened to the atmosphere. Doesn’t meet the code definition in residential housing but better than just removing anti-siphon valve.

Now that I think about it. I should probably do this on my own trailer.


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JohnDar

Prolifically Gabby Member
After ours failed, hidden in an inaccessible wall cavity, I pulled the lines down, cut them shorter and used a Sharkbite check valve to join them. Prior to that, I had replaced the cheap plastic inlet for the flusher after it broke in the UDC with a brass city water inlet with a check valve.

Any owner, if you can access the garbage OEM plastic ASV, replace it with a brass one before it gives you grief.


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61Hawks

Member
I need help. I have a 2015 c300 and my ASV has failed. Water filled my underbelly and the last flush I can hear water spraying in the wall beside the toilet. I am assuming it is there as I removed the wall in the basement and saw the lines running up there. I couldnt pull them down as was suggested by someone. How do I get to the ASV? Can I access from behind the switch center or do I have to cut a hole in the wall beside the toilet. If that is the case how high up is it as I cant see up the wall from the basement.
 

cookie

Administrator
Staff member
You shouldn't have to cut a hole in the wall.
Many times the ASV is located behind a cabinet, screwed on wall panel or accessed through a round access hole in the shower wall. You mentioned switch center, look behind that.
Worst case you could do what many others have done, cut the two PEX lines going up and splice them together.

Peace
Dave
 

JohnDar

Prolifically Gabby Member
Pull harder. Mine wasn’t attached to anything. Or as Cookie suggested, just cut them and splice in a check valve.


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