Why is my Zoeller Sump Pump Switch Not Working?

Today we got a call from a nice guy who asked, “do you sell sump pump parts”? Well, that’s a pretty broad question. There are probably a dozen sump pump manufacturers and each one has hundreds of different parts. So I asked, “what part are you looking for?” He told me he had a Zoeller sump pump and that he needed a switch because his wasn’t working. I told him we don’t just sell parts, we fix and replace sump pumps (as we do for all parts of the plumbing system). But, I wanted to see if we could help him so I shared our field knowledge on Zoeller sump pump switches. 

Here in the greater Akron area, the M53 “Mighty Mate” is Zoellers’ most commonly installed residential sump pump. We don’t install them for the same reason this guy called. Their switches are prone to failing due to short cycling. Don’t get me wrong…Zoeller makes a very heavy-duty, powerful motor, durable housing, and a well-protected float mechanism. The problem is that their switch design doesn’t do well in sump crocks that get a lot of water coming in. When the crock has a lot of water coming in the pump goes on and off a lot. This causes the switch mechanism to overheat and the metal tabs in the switch to get stuck together – they basically fuse together. So the motor gets stuck in the on position and keeps running even after all the water is pumped out. This causes it to overheat and burn out. And the next time the water starts filling up the pump is useless and the basement floods. We see it all the time. 

This is directly from Zoellers website: 

My automatic pump stops and starts constantly, how can I make the pump run longer?

This is called short cycling. It is a function of the basin diameter and the “on/off” pumping range. If you have an automatic unit which has a self contained float switch the “on/off” pumping range cannot be adjusted. Short-cycling can decrease the service life of a switch assembly. If this occurs, an automatic unit can be converted by using a long-cycle kit (P/N 10-0001) or by using a non-automatic pump with a piggyback variable level switch, which will expand its pumping range and decrease the amount of short-cycling. 

There’s way more to repairing and selecting the proper sump pump than people realize. Notice they mention the solution – changing to a long-cycle kit or using a piggyback variable level switch. BUT….the model that the local suppliers carry comes standard with the switch that is prone to short cycling. 

You see anyone can sell parts. But it’s the expert, the guy who has the field knowledge, that can provide solutions that keep your basement dry and save you money in the long run. This guy didn’t want to pay for us to come out which was too bad. We probably could have saved him from wasting his money by installing the same failure-prone switch and maybe from a flooded basement. 

I wonder if he had even found the serial number on the unit and checked to see if it was still within Zoellers 3-year warranty. Oh well, I guess I’ll never know. 

There are solutions out there and our job is to educate homeowners on what they are. Maybe next time.