rvupgradestore.com Composet Products Fridge Defend
RV Life Magazine RV Park Reviews RV Trip Wizard

Author Topic: washing machine grey water pump?  (Read 8749 times)

andonso

  • ---
  • Posts: 25
washing machine grey water pump?
« on: August 01, 2019, 06:10:02 PM »
Hello,

I'm wondering if there is a way to pump washing machine grey water (installed in a shed)  into a septic system where there doesn't appear to be enough slope to naturally drain via gravity the grey water into the septic tank.

Either pump straight into the septic or into a large 200 gallon holding tank then pump into the septic tank.

What would be the best type of pump to look for?

I'm uncertain about pumping grey water into a tank destined for the septic.

HueyPilotVN

  • ---
  • Posts: 1948
Re: washing machine grey water pump?
« Reply #1 on: August 01, 2019, 06:25:50 PM »
Use a macerator pump.
Bill Waugh
40' Country Coach DP
2 Jeep Commanders
Mustang Bracket Race Car
Retired from the road to Lake Havasu after 35 years on the road

darsben

  • ---
  • Posts: 1685
  • Retired seeing the USA
Re: washing machine grey water pump?
« Reply #2 on: August 01, 2019, 06:56:22 PM »
If it was me and only the washing machine was involved I would use a sump pump.
1990 Fleetwood Southwind on P30 chassis located in
Central NY in summer and beautiful Casa Grande AZ in winter

Lou Schneider

  • Global Moderator
  • ---
  • *
  • Posts: 9776
Re: washing machine grey water pump?
« Reply #3 on: August 01, 2019, 09:05:57 PM »
Before you get too involved, verify the slope to the septic tank inlet using a garden hose water level.

Run a hose between the two points, raise both ends the same distance above the proposed plumbing (taking into account the depth of the septic tank inlet below ground) and pour water into one end.

If the water comes out of the other end water will naturally drain out of a tank.  You can put something like a 50 gallon drum above ground at the washer if you need to gain elevation.

You can also get attachments that show the water level at each end of the hose:

https://www.amazon.com/Mayes-Level-10309-Water/dp/B00004YZP8

« Last Edit: August 01, 2019, 10:03:49 PM by Lou Schneider »

Isaac-1

  • ---
  • Posts: 2522
Re: washing machine grey water pump?
« Reply #4 on: August 01, 2019, 09:52:07 PM »
Also keep in mind that a washing machine drain stand pipe is by code set at a height of 30-96 inches above floor level (depending on location), most are at a height of 39-42 inches, therefore most (all?) washing machines can internally pump their drain output up to 96 inches above floor level.  GE specifically states in their installation manuals that the stand pipe must be between 24-96 inches, be 1 1/4 inch in diameter or larger, and flow at least 17 gallons per minute.

This added standpipe height may be enough to gravity drain in your situation.  If not then you can look into a variety of pump options.
2002 Safari Trek 2830

Arch Hoagland

  • ---
  • Posts: 3092
  • Clovis CA
Re: washing machine grey water pump?
« Reply #5 on: August 01, 2019, 09:56:44 PM »
Put the washer up on a stand to gain a foot or so?

What Isaac-1 said may cure the problem too. Didn't know that.
2004 Monaco La Palma 36 DBD
W22, 8.1 gas,  Allison 1000 Transmission
7.1 MPG over 90,000 miles

2000 Lexus RX300, 4020lb
U.S. Gear Braking System

Lou Schneider

  • Global Moderator
  • ---
  • *
  • Posts: 9776
Re: washing machine grey water pump?
« Reply #6 on: August 01, 2019, 10:05:13 PM »
I never knew a washer could pump it's drain water that high, but I guess it makes sense for a basement installation where the drain lines are near the ceiling.

HueyPilotVN

  • ---
  • Posts: 1948
Re: washing machine grey water pump?
« Reply #7 on: August 01, 2019, 10:35:07 PM »
I recently installed a washer and dryer in the RV garage for Renae's daughter Kelly.

I initially ran the drain hose into the floor drain for the RV dump.

The washer would not empty all the water during the spin and drain cycle.  I put a 40 inch tall plastic pipe into the drain and moved the discharge hose up to the top and it now works the way it should.

I would have thought that it would drain better when flowing in top a lower level, not so.
Bill Waugh
40' Country Coach DP
2 Jeep Commanders
Mustang Bracket Race Car
Retired from the road to Lake Havasu after 35 years on the road

andonso

  • ---
  • Posts: 25
Re: washing machine grey water pump?
« Reply #8 on: August 07, 2019, 02:52:17 PM »
We're also going to be installing a shower and a sink so would require a central drain otherwise a washing machine pump by itself might create enough pressure to push water to a 4 inch sewer drain.

I never did bother using a water level which I remember using years ago while working in the shipyards. Looking at the ground points where water drains from the shed and the 4 inch sewer line inlet I'm fairly certain the sewer is at least slightly above the shed and it's drain. 3 in. sewer drains require at least 1/4 in. drop per foot.

Update:

What we did was find a sump pump and install it in the bottom of a plastic tank that was lowered to below ground level. Ran a 3" grey water drain line to the side of the plastic tank , install the sump pump on the bottom of the tank, then run a line from the sump pump over to the 4 inch sewer line to the septic.

Filled the plastic tank with grey water and the pump turns on automatically at around 6" level and off at around 2" water level. The Zoeller sump pump is able to handle up to 1/2 inch solids.

The plastic tank must be around 200 gallons but never actually fills up as the Zoeller sump pump, pumps around 40 gallons / min with a 5 foot head and the plastic tank is only sunk into the ground approx. 4 feet, where the sump pump only needs to push water approx. 4 feet vertically and 10 - 15 horizontally.

Found a good deal on a Zoeller M53-D sump pump for $65.00 from Offer Up. Works great no problems.

« Last Edit: August 07, 2019, 03:07:49 PM by andonso »