Plumbing for Dishwasher and Washing Machine

[Mark Thurlow]

I have a fitted dishwasher and washing machine in my Moody 49. They work well. They are plumbed to drain into a separate sump box in the bilges with a bilge pump in the sump box.

However when the machines drain the pump is overwhelmed. Fitting a bigger pump here is not an option. When the water fills the sump box there is a risk of water splashing onto electric fittings.

Is there a reason why I cannot connect these directly to an under water skin fitting or above waterline drain.

I am told the machines do not have pumps that will over come water pressure!

What's the advice people.

I do not need advice on gray water disposal please - I understand this aspect and apply the rules. Its the internal pumps and pressures that is the question?

[ericoh88]

Mark

Have you considered adding a T to another new shower sump with pump and separate discharge above water line?

I have a washing machine onboard. Mine are drained to a sump below the shower wooden grating because the washing machine sits on the seat in the shower room. The water flows to a shower sump box with pump which is discharged below water line.

I am going to relocate this discharge outlet to above water line next haul out and seal the old hole. One less hole below water line.

Eric

[Dockhead]

My Moody 54 has a washing machine from the original build, and the waste pipe is plumbed into the aft gray water tank. The Whale Gulper 220 easily deals with the flow.

If you upgrade your pump you should be okay.

You can also plumb into an above the waterline sea cock. Precautions have to be taken against flooding risk, however. I don't know if your machine will pump against an anti-syphon loop - probably not. So you'll have to keep the sea cock closed whenever you're underway, and never, ever forget.

So maybe upgrading the pump would be better.

Sent from my D6633 using Cruisers Sailing Forum mobile app

[ColdEH]

I plumbed my waste water from my Splendide washing machine directly into the scupper down tube , it discharges below water line . I put a one way flapper valve on it for when it really rains and the suppers are over whelmed , works just fine if you have scuppers on you boat ,

Regards

[jeremiason]

We have a Splendide Washing Machine/Drier on our Catalina 470...


It is plumbed to discharge through an underwater thruhull and works fine.


You are not talking about huge pressures here.... Discharging through a thruhull probably has less head pressure than going up a wall to a drain in a home installation

[Terra Nova]

Connect it to an above-waterline drain with sea cock that can be closed, if necessary, in rough sea conditions.

Those sumps are intended to evacuate the trickle from a gravity fed shower drain, not the blast from a high output washing machine pump.

[Dockhead]

Originally Posted by jeremiason

We have a Splendide Washing Machine/Drier on our Catalina 470...


It is plumbed to discharge through an underwater thruhull and works fine.


You are not talking about huge pressures here.... Discharging through a thruhull probably has less head pressure than going up a wall to a drain in a home installation

Just be sure that you have covered any flooding risk.

[Mikado]

My Haier washing machine drains thru an above waterline thru-hull with seacock. It pumps the water past the anti-siphon loop with no problem but I'm sure every machine is different.

[Orion Jim]

I don't want to make light of your concerns but I wish I had the same problem.....and the Moody would be appreciated also.
Hopefully one of the recommended fixes works for you.

[Dockhead]

Originally Posted by jeremiason

We have a Splendide Washing Machine/Drier on our Catalina 470...


It is plumbed to discharge through an underwater thruhull and works fine.


You are not talking about huge pressures here.... Discharging through a thruhull probably has less head pressure than going up a wall to a drain in a home installation

I'm not sure it has any pressure at all if the washing machine is above the waterline.

[Mark Thurlow]

Jim, Your are right the Moody 49 is a winner, we feel lucky on our journey!

[poiu]

Mine has a relay activated by the machine pump, that switches an extra pump in series that pumps through a check valve, over a siphon loop with a break valve, then out through a waterline through hull.

[Pelagic]

Originally Posted by Mark Thurlow

I have a fitted dishwasher and washing machine in my Moody 49. They work well. They are plumbed to drain into a separate sump box in the bilges with a bilge pump in the sump box.

However when the machines drain the pump is overwhelmed. Fitting a bigger pump here is not an option. When the water fills the sump box there is a risk of water splashing onto electric fittings.

Is there a reason why I cannot connect these directly to an under water skin fitting or above waterline drain.

I am told the machines do not have pumps that will over come water pressure!

Mark, if I understand, the problem is that the small dedicated sump box (made smaller by an internal pump and probably float switch) is simply overwhelmed by the appliances pumps.

In other words the small box volume defeats the efficiency of the submersible sump pump

Have you considered removing that sump pump from inside box and making that box a sealed strainer/reservoir.

Then fit downstream an inline pump activated either by relay or sensor inside sump box.

Advantage of sealing that sump box is you never need to worry about splashes/smells/electrics.

Advantage..You can also first test if appliance pumps can discharge on their own.

[Pelagic]

Mark, if I understand, the problem is that the small dedicated sump box (made smaller by an internal pump and probably float switch) is simply overwhelmed by the appliances pumps.

In other words the small box volume defeats the questionable efficiency of the submersible sump pump

Have you considered removing that sump pump from inside box and making that box a sealed strainer/reservoir.

Then fit downstream an inline pump activated either by relay or sensor inside sump box.

Advantage of sealing that sump box is you never need to worry about splashes/smells/electrics.

Advantage..You can also first test if appliance pumps can discharge on their own.

[Lepke]

The easiest way is to discharge directly overboard via an above the waterline fitting. All the washer pumps I have run into will support pumping thru at least a 3' loop and anti- siphon fitting. Have a shutoff.
My house size dishwasher only dumps about 25% of the water that the washer does and is just emptied into the galley sink drain.