Sump pump replacement

A few weekends ago, I decided it was time to put some work into my sump pit.  My pump was acting up (the switch was sticking on intermittently), so that gave me an excuse to dedicate some time and thought to it.

When we moved into the house it came with a 1/3 hp Sears brand pedestal pump.  Although it was quite crusty, and I considered it to be under powered for the job, it was actually a very reliable pump.  It was already a few years old when we moved in, and then it lasted another 16 years, giving it a service life of almost twenty years!  When it finally did fail, luckily I was alerted by my HomeSitter alarm.  I found the pump with the switch in the on position, but it wasn’t running.  Because the water level kept rising, the motor housing was already partially submerged (I have a deep pit).  I knew that it was time for a new pump.  I figured why not replace it with another Sears unit, since this one lasted so long.  I rigged up a utility pump to drain the pit temporarily so I could run to Sears and pick up a new unit.  What they had was a 1/2 hp Craftsman brand pedestal pump.  It seemed to be built very well, with a cast iron base and stainless steel stem.  To top it all off, it came with a lifetime warranty! (I am a sucker for lifetime warranties, although a certain quote from Tommy Boy comes to mind…)  It was almost a direct replacement.  The old pump was 1-1/4″ and the new one was 1-1/2″.  Luckily the pipe was all 1-1/2″, with a reducer on the bottom.  I cut off the old reducer and glued on a new 1-1/2″ threaded fitting, and it was in!

Unfortunately, despite it’s impressive build quality and lifetime warranty, here I am again looking for a replacement pump two years later.  This time I was facing the opposite problem.  The pump wouldn’t turn off!  I would find it running, with the switch fully in the downward position.  The first time it happened, I toggled the switch and it turned off.  Thinking it was just a fluke, I forgot about it.  But then it happened again the next day, and the next day.  And I finally realized the switch was on it’s last leg.  This shouldn’t be an issue though, right?  I have a lifetime warranty to fall back on!  Wrong.  Sears discontinued the model I bought, and the only model they did sell under the Craftsman name no longer has a lifetime warranty, not to mention it is a 1-1/4″ pump with a less impressive flow rate.  Sears corporate may have failed me, but luckily the manager at my local Sears hardware store did their best to make me a satisfied customer.  Because they no longer make an equivalent Craftsman/Sears pump, they made an exception and allowed me to have my pick of which pump I wanted from the plumbing isle for a one time exchange.

Left-Basement Watchdog Special, Right-Zoeller M98.  I used a square rubber patio paver that I cut the corners off of to make a nice bottom in the pit.  It’s important to keep cables neat and tidy so they don’t interfere with float operation.

The pump I ended up choosing is the Zoeller M98.  It is a 1/2 hp submersible pump, with 1-1/2″ discharge, and a very similar flow rate to my previous pump (61 GPM@10ft lift).  It has a cast iron housing, and is built like a tank.  If I wasn’t limited to what they had on the shelf, I would have choose a Zoeller N98.  It is the same pump, but without the built in float switch.  The unfortunate fact of many sump pumps is that the float switch fails long before the pump itself.  That is why the good folks over at TouchSensor Technologies have created the LevelGuard pump switch.  It has no moving parts to wear out and fail, allowing it to last just as long (if not longer) than your pump.  But the key is to get a pump without an integrated float switch (Zoeller pumps that start with an “N” come without a switch).  If the float switch on my M98 ever starts acting up, I plan on converting it to an N98 and installing a LevelGuard switch.

Battery and control unit for backup pump

Up until now, I have been lucky enough to be home each time my primary pump has failed.  My fear has always been that it will happen when I’m not home.  Since I was going to be putting in a new primary pump, I figured this would also be a good time to install a backup pump.  The backup pump system I choose is the Basement Watchdog Special.  It seems to be a good value, it’s the middle model between the “Emergency” on the low end, and the “Big Dog” on the high end.  It will pump about 28 gallons per minute (GPM) at a ten foot lift, which is a few GPM shy of half the capacity of my primary pump.  For a small 12v backup pump running off of a battery, the lower flow rate seems reasonable.  Most of the time, it wouldn’t have any trouble keeping up.  Obviously there is a chance that at some point, the water could be flowing into the pit faster than it can pump.  But I would much rather have it pumping water out at 28 GPM than 0 GPM without it!  And of course, all of this is only a factor if the primary pump has failed or the power is out.

The “wye” and check valves. Be sure to use the proper cement for the type of pipe you have. I had to use a multipurpose cement because I have a combination of PVC and ABS.

Installing the new primary pump was a breeze.  Because my new M98 is 1-1/2″ discharge like my old pump, I was able to reuse the old pipe and fitting.  The backup pump installation required a little more work.  I had to cut out a section of pipe above the existing check valve to install a 45 degree “wye” fitting.  The new pipe for the backup pump then comes out of the wye, goes to a 45 degree elbow, and and then goes down to the backup pump.  It is very important to have a check valve below the wye fitting on both the primary pump pipe, and the backup pump pipe.  This keeps water from flowing out through the backup pump while the primary pump is working, or vice versa.  After getting all the plumbing done, I filled the battery with acid, topped it off with distilled water, and hooked up all of the wiring.  The backup pump comes with it’s own float switch that zip ties to the discharge pipe.  You want to make sure that the float for the backup pump is at least a few inches above the water level that would normally kick on the primary pump.  I also drilled a 1/8″ hole at a 45 degree angle pointing down on the pipe above the backup pump.  This prevents the pump from becoming airlocked (when air gets trapped in the impeller housing, preventing the pump from moving water).  This isn’t necessary for my primary pump (M98), since it already has a hole in the impeller housing to prevent airlock.  All in all, installation was fairly straight forward.  I am very happy with the way things turned out, and I feel much better knowing that I now have a backup system in place.

Quick overview of my setup:

So, what should you take away from this?  An ounce of prevention is worth a pound of cure.  Take the time to install a quality primary and backup pump, and you will have a dry basement.


2 Responses to “Sump pump replacement”

  1. Ron Freier says:

    My battery five years old. The yellow light is lit and continues to beep even after I filled the battery to cover the plates. The pump functions manually when I press the yellow button on top.What do I do next?

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