Sump (Waste) Pit cover replacement

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Well-Known Member
May 15, 2008
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I've got a waste ejection pump that serves the bathroom in my basement. The concept is pretty much identical to a sump pump, except for the possibility of excrement.
This means that the lid should be sealed and connected to the vent stack (which it is/was).

Ok, so what happened is the pump stopped working, the pit overflowed a bit ... so I had to open up the pit.
The lid, which was metal (and two pieces) was very rusted and I wound up cutting some of the bolts. The pit itself is a hard plastic and seems fine.
I discovered the pump was fouled, unfouled it, and it now works again.

So all I need is a new lid, and the various seals to go around the pipes and around the whole lid too.
Unfortunately, I have no clue what the make of the pit-bucket is. The pump is a Zoeller.
The pit bucket is 18" inside diameter and has 24 evenly spaced bolt holes (4 of which would require work to remove the remains of a cut bolt).
The old lid was 20.5"

Searching online, I mostly find covers that are clearly intended for regular sumps, as they would be hard to make air tight. I don't see any that have holes for the bolts of the pipe seals, nor have I yet found such seals themselves. I might be searching with the wrong words. Maybe you're supposed to tap such holes yourself? If so, might it make more sense to buy a solid cover and cut any holes I want (which would save me having to slightly reposition one or both of the pipes).

What is my next move supposed to be here? I can post pics of the existing situation and the pieces I had to remove.

There are plastic lids made just for sewage ejector pumps.

I will look for a link.

I usually get mine from Ace Hardware.

They come with a foam gasket for underneath the outside edge, and two seals that slip over the 2 inch pvc pipes and seal against the top of the lid.

They also have a grommet for the pump cord.

They have knockouts for the two pipes, which are often in the wrong place.
Sometimes they are already open, which is a problem when in the wrong spot.
So maybe look for one that is not already drilled.

Just cut holes with a hole saw or jig saw.
About eight screws through the lid into the rim of the sump tank will hold it down well.
Some people also caulk around the outside edge.

You will probably have to cut or take apart the pvc pipes, to slip the new cover over them.

You can repair with no-hub couplings.

You can probably get the cut bolts out by grabbing with vice-grip pliers.
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Thanks Jeff - that's really good to know that I was on the right track thinking I should cut the holes myself in a solid cover. That way I can put them exactly where they will match up with the existing sewage line and vent stack line.

Good news about the existing piping is that I won't have to cut it - there were two slightly flexible sections - not sure what you call them, around a one-way flap valve in a metal body. By loosening the (four) hose clamps involved I was able to disconnect the pump outflow from the house before I removed the old cover.

I need to go refresh my memory of what's down there. I think I need two 3.0 flanges. I can reuse the existing cord grommet.

Thanks again!
If I run into trouble, I'll hit you up for more advice, but this is looking good.

(When I discovered the problem, I did a quick search to find out roughly what a plumber would charge. I think I've saved myself a thousand bucks!)
Read the specs on the flanges.
Look at actual circumference, and inside diameter of the hole inside, and what size pipe they are for.

Some are flat, and some have a rim that slips into the hole in the cover.
Good advice - and I won't do any cutting until I have all the pieces in hand. Presumably any imprecision in my jig-sawing can be remedied with silicone caulk.
Use the old cover for a template.

If cover is gone, measure from several points for hole locations.

Cut clean holes, take your time, use a high tooth count blade, saw slowly or it melts and needs more filing or shaving with a razor.

Trace around something laying around that is the right hole size.
I just realized I can reuse the old flanges - they are ABS. I had to scrape off the grey seal that had become thoroughly embedded by rust. So all I need is that seal. Is it a piece of rubber-like material that I can buy, or is it just some specific sort of caulk? It peeled away like it had been one piece.

Good suggestion about a hole saw set. I have a small hole saw set for drywall, and it's great for that.
The seal is usually just a roll of foam weatherstrip, 1/4 or 3/8 approx thickness.
You will see it on that same linked page with the seals.
Anything similar off the shelf should be fine.
Then caulk around the rim after screwing down, if you want, optional.

Screw the lid down with small stainless screws and appropriate stainless washers, usually small fender washers work well.
Had the same issue with a rusted lid. I still had the original receipt for the tank from 1990 but it didn't specify the brand. The plastic lid from HD fit fine. It came with sealing tape but I added a thin bead of caulk around the rim after the install to be sure.
I finished the job with stainless steel bolts yesterday. Had do go up a size on the bolts to use the old holes.
I also had to do a slight bit of shaving material to fit because the new lid was about a millimetre too wide.

Total cost: Around $35, plus a silly amount of effort. I only had to cut one hole, so I didn't bother getting the hole saw. Still, beats paying a plumber!