Grey water pipes question

[Bonjoey]

Hopefully somebody have more knowledge on Sunseekers can answer my question. It happened twice now that our kitchen sink overflowed before the shower did, I thought the sink was clogged and when try to pump it, it bubbles and slowly drained but not all.
Our previous tt overflows the tub first before other drains.

I always thought the shower/tub was the lowest point on the grey pipes, that it will overflow first before other drains? Or is this a safety feature so that the shower will not overflow when the grey tank is almost full.

[nomad297]

Your shower most likely has a HepvO “waterless trap” instead of a traditional p-trap. The HepvO trap will act as a check valve and will not allow water to flow towards the shower.

Bruce

[Bonjoey]

Originally Posted by nomad297

Your shower most likely has a HepvO “waterless trap” instead of a traditional p-trap. The HepvO trap will act as a check valve and will not allow water to flow towards the shower.

Bruce

Thank you. I will try next time to fill the shower when the kitchen sink started to overflow again.
The brochure says Sunseekers have waste tank capacities of 39 gallons each. Ours doesn’t feel like 39 gallons

[Shredder]

Be careful if the trap in the shower seals due to back pressure of water and you fill the shower and the waterless trap opens you might have a bigger mess on your hands then you want.

What does your gauge say when the sink backs up?

Full ?? 3/4??

Anyhow good luck i usually keep the grey open until i'm about to break camp and need the grey to flush the black away.

[Bonjoey]

Originally Posted by Shredder

Be careful if the trap in the shower seals due to back pressure of water and you fill the shower and the waterless trap opens you might have a bigger mess on your hands then you want.

What does your gauge say when the sink backs up?

Full ?? 3/4??

Anyhow good luck i usually keep the grey open until i'm about to break camp and need the grey to flush the black away.

Thank you. Good thing we didnt use plunger to pump it.
Gauge says full when it starts to overflow.

[TitanMike]

Originally Posted by Shredder

Be careful if the trap in the shower seals due to back pressure of water and you fill the shower and the waterless trap opens you might have a bigger mess on your hands then you want.

Considering that the sink is much higher and is exerting far more pressure against the "trap", very doubtful that even a shower pan full of water will have enough pressure to open it.

Water pressure in pipes not pressurized by a pump is determined by "head" which is the height of the source. Sink is higher thus greater head pressure.

[nomad297]

Originally Posted by TitanMike

Considering that the sink is much higher and is exerting far more pressure against the "trap", very doubtful that even a shower pan full of water will have enough pressure to open it.

Water pressure in pipes not pressurized by a pump is determined by "head" which is the height of the source. Sink is higher thus greater head pressure.

Exactly.

Bruce

[gbaldwin]

Originally Posted by Bonjoey

Thank you. Good thing we didnt use plunger to pump it.
Gauge says full when it starts to overflow.

sounds like gauge is working accurately for now. watch the gauge and dump more often

[nomad297]

Originally Posted by Bonjoey

Thank you. I will try next time to fill the shower when the kitchen sink started to overflow again.
The brochure says Sunseekers have waste tank capacities of 39 gallons each. Ours doesn’t feel like 39 gallons

You’re welcome. I think that we all feel that our gray tanks aren’t as big as they really are — it’s very easy to use more water than you really need to use when cleaning dishes and brushing teeth, etc. The boondockers here have all of that worked out, though.

Your idea of running water in your shower to verify the existence of a HepvO trap is a good one.

Bruce