outdoor sink not draining when pump on

[Steve L-THOR]

My outdoor sink in 2016 29M is not draining when I switch on the macerator pump. It actually 'backwashes' a bit. I disassembled the plumbing I could access to look for a clog. Found none in this short section. (now is tough to reconnect with the the unexpected flex liner). Any ideas?

All other plumbing, grey and black tank drains, working fine.



Thanks for any help.

Steve L.

 

[Lt Keefer]

My 2018 29M quit draining last year. I rarely used it, but still. I cleaned all the plumbing and it still doesn't drain. My pump runs, but don't know if the impellor is turning. Any way, since I rarely use it, I kind of gave up.

 

[Steve L-THOR]

Thanks Lt. May go the same way as we also very rarely use it. Did yours have the peculiar rubber insert connection in the PVC?

 

[PS89]

They all have that "peculiar" insert in the drain. It's a one-way waste check valve.

More likely than not the pump's impeller has worn out and it's no longer sealing against the wall of the pump's cavity as it rotates. I had to rebuild mine this spring. Used this part:

https://www.amazon.com/dp/B09RLXZLB2?ref=ppx_yo2ov_dt_b_fed_asin_title&tag=amzfinder-20

 

[Lt Keefer]

Yup, that funny thing is a p trap replacement. It keeps the smell out. I've debated routing a hose off the sink and letting it drain on the ground. It's on my winter project list after new seats.

 

[dkoldman]

Yup, that funny thing is a p trap replacement. It keeps the smell out. I've debated routing a hose off the sink and letting it drain on the ground. It's on my winter project list after new seats.

My SOB has same insert on outside sink. No macerator pump but a ShurFlo pump that pumps it all to the black tank.

A while back I updated the momentary switch to an On / Off. We use all the time to keep some stuff out of the inside of RV

 

[Bob Nodine]

I would be breaking down the macerator to see if it clogged or the rubber impellers are worn out.

 

[Lt Keefer]

I would be breaking down the macerator to see if it clogged or the rubber impellers are worn out.

The deal is, the amount of space to work in is very limited. I lost a lot of skin off the back of my hands just getting the trap out. The macerator is even farther back and in less space. For as infrequently as I use it, the hose route is going to be a better option.

 

[Jimbo57]

Slow drain

My outdoor sink in 2016 29M is not draining when I switch on the macerator pump. It actually 'backwashes' a bit. I disassembled the plumbing I could access to look for a clog. Found none in this short section. (now is tough to reconnect with the the unexpected flex liner). Any ideas?

All other plumbing, grey and black tank drains, working fine.

View attachment 47408

Thanks for any help.

Steve L.

I don’t know anything about macerated type plumbing but why would that stop me from putting in my 2 cents. Since those tube are in the drain lines could you use garden hose with nozzle and squirt water down inside lines and in the pipe outside the pink lines to clear for air gap

 

[PS89]

About the macerator pump, it's just a pump that adds a set of blades (look almost like mini blender blades) at the inlet. Not sure why Thor thought it necessary to use anything but a water pump for that sink.


I've attached a copy of the manual.

 

[MJC68]

About the macerator pump, it's just a pump that adds a set of blades (look almost like mini blender blades) at the inlet. Not sure why Thor thought it necessary to use anything but a water pump for that sink.


I've attached a copy of the manual.

Hmm, just spit balling here, but if you wash dishes with food particles and then suck the drain water through a shurflo style water pump what are the chances the pump takes a dump? Perhaps that's the reason for a macerator?

 

[dkoldman]

Hmm, just spit balling here, but if you wash dishes with food particles and then suck the drain water through a shurflo style water pump what are the chances the pump takes a dump? Perhaps that's the reason for a macerator?

True, but because the outdoor kitchens have a built in metal strainer insert, no particles can get through. I believe in post #4 they call it a "peculiar insert" but we use all the time. Esay to remove and clean. Our SOB has a Shur-Flo pump but no macerator. I don't see the need of macerator. I think it is only a pump at all because the sink is so low that a pump is required to pump to a rise holding tank, in our case that holding tank is a black tank which helps getting more liquid in that the Black. It also has the tank Thetford chemicals to further break down what particles that may have slipped through.

 

[16ACE27]

Hmm, just spit balling here, but if you wash dishes with food particles and then suck the drain water through a shurflo style water pump what are the chances the pump takes a dump? Perhaps that's the reason for a macerator?

They don't need a diaphragm type pump, a simple centrifugal pump ;ike used as bilge pumps would work fine.

 

[OldWEB]

My outdoor sink in 2016 29M is not draining when I switch on the macerator pump. It actually 'backwashes' a bit. I disassembled the plumbing I could access to look for a clog. Found none in this short section. (now is tough to reconnect with the the unexpected flex liner). Any ideas?

All other plumbing, grey and black tank drains, working fine.

View attachment 47408

Thanks for any help.

Steve L.

Now that looks like a P-trap replacement or what is known as a HEPVO valve, which is just a membrane that seals after the sink drains. It looks like yours has prolapsed and inverted itself "inside out", how or why is interesting. Just push it back in carefully...

 

[OldWEB]

They don't need a diaphragm type pump, a simple centrifugal pump ;ike used as bilge pumps would work fine.

Where did I get lost... why is there a pump in the first place? Is the drain actually lower than the tank it flows into, can someone clarify it for me?

 

[PS89]

Is the drain actually lower than the tank it flows into,

Yes it. Liquids won't flow uphill.

 

[Lt Keefer]

True, but because the outdoor kitchens have a built in metal strainer insert, no particles can get through. I believe in post #4 they call it a "peculiar insert" but we use all the time. Esay to remove and clean. Our SOB has a Shur-Flo pump but no macerator. I don't see the need of macerator. I think it is only a pump at all because the sink is so low that a pump is required to pump to a rise holding tank, in our case that holding tank is a black tank which helps getting more liquid in that the Black. It also has the tank Thetford chemicals to further break down what particles that may have slipped through.

Sorry, but Thor didn't put a metal strainer in the outdoor sink. It's a pop up sink plug. Glad you posted though, because the pop up plug may have a strainer. Now I'll have to remove the pop up, disassemble and clean. That may be my problem. I mostly used the outdoor sink to clean utensils and grill parts.
My problem may be a grease build up on the internals of the pop up. I wonder what drain cleaner would do to an RV holding tank.