Bought my house a year ago. We need a sump pump under our laundry basin because of gravity. Never thought much of it until it wouldn't shut off yesterday, but wasn't pumping any water.

I pulled the sink out and looked at it, it is all mouldy and gross. My guess is that it hasn't been replaced (or cleaned) since the house was built in the early 90s, and is probably jammed with all kinds of lint, cat fur, etc.

Replacing it is quite easy in theory, but in practice maybe not so much.

Here are some pictures of my situation:
imgur: the simple image sharer (http://imgur.com/QTeSV)
imgur: the simple image sharer (http://imgur.com/qplZV)
imgur: the simple image sharer (http://imgur.com/doh6D)
imgur: the simple image sharer (http://imgur.com/xw3y6)

Question 1: As you can see, the PVC drain pipe connects almost at the bottom of it. The pump seemed to twist in this connection only... is this a threaded connection? How is it most likely connected?

Question 2: How thick is that PVC pipe? Is that a common connection to a sump pump?

Question 3: Is this going to be easy to replace? If it connects at the very bottom there isn't very much room to manoeuvre with it.

Any help is HUGELY appreciated. Thank you in advance!

Question 1: As you can see, the PVC drain pipe connects almost at the bottom of it. The pump seemed to twist in this connection only... is this a threaded connection? How is it most likely connected?

Yes, the first thing out of the pump housing is a threaded adapter. The adapter is threaded into the pump then pipe is glued to the adapter. The piping is ABS not PVC. Basically the same thing as PVC but you must use ABS glue.


Question 2: How thick is that PVC pipe? Is that a common connection to a sump pump?

Probably Schedule 40. Yes


Question 3: Is this going to be easy to replace? If it connects at the very bottom there isn't very much room to manoeuvre with it.
Yes, very easy replace. You cut the pipe in the horizontal run, lift the pump out of the hole and replace it. Pipe can be cut with just about any kind of saw. To install new pump you would screw in a threaded adapter, glue in a vertical pipe, 90 degree elbow,and a short piece of horizontal pipe. Sit you new pump with piping installed in the hole. Cut the horizontial pipe to match the horizontial pipe from the drain and reconnect.
You can reconnect with a glue up coupling or a rubber coupling. Probably should use a rubber coupling. From the number of couplings in the existing pipe, it looks like the pump has already been pulled a couple times.

Before you go replacing the pump grab that float and shake it well. The fault is in the float switch and not in the pump itself. Since it is a water tight device I doubt that it is serviceable but appearently it is just stuck in the on position.

Look at the connection where the float wiring connects to the pump wiring. Can't tell from the picture, but is that just a connection or is it a manual/auto switch.
Float is probably replaceable but you will probably have a hard time finding a replacement.

If you proceed with pump replacement and are really cheap, you can cut the horizontial pipe about 2 to 3 inches from the elbow next to the pump. Unscrew the piping from the old pump and screw it into the new pump and reconnect.
You may or may not be able to find ABS piping in your area. It is used for the same purposes as PVC and is only a few cents cheaper than PVC. Plumbing supply houses in some areas have stop stocking both ABS and PVC pipe. ABS fittings are usually available. You can switch over to PVC piping but you must use an all purpose glue or the rubber coupling to connect the PVC to the ABS.

All in all this is about a 30 minute task.

Are you done yet?

Wow, amazing. Thank you so much!!