The $43 Dilemma: Zoeller M53 vs M57 Sump Pump Cost

I like saving money when I can but I still buy quality products despite the cost. For me the Zoeller M53 vs M57 sump pump question boils down to how long I am going to live in the house. If I am staying five years or less, I’ll buy the Zoeller M53. However, if I know that the pump must deal with a lot of sand and grit, I would buy the Zoeller M57 because it has a longer lasting cast iron impeller. Whereas the Zoeller M53 has a plastic impeller.

Both pumps are excellent purchases. If the extra $43 (at time of writing) isn’t an issue, then buy the Zoeller M57. 

Five times more people buy the Zoeller M53 sump pump than the M57 model. So, you can save some money and still get an excellent sump pump by buying the Zoeller M53 sump pump. 

You can read my full review of the Zoeller M53 sump pump – Click Here

Comparing the Zoeller M53 vs M57

The two sump pumps are identical except for four main features, plus the price difference.

Both pumps are part of the Zoeller Mighty Mate 50 Series. There are two other pumps in the Zoeller 50 Series. The Zoeller M55 and the Zoeller M59 which are made of bronze instead of cast iron. They cost 10 times more than the M53 and M57 models.

O.K. lets get into the details.

The Most Important Zoeller M53 vs M57 Difference

All of the Zoeller sump pumps have non-clogging vortex forming impeller. Basically, it makes the water move with little contact with the water that is pumped out. Which reduces the chances of the impeller wearing out or getting stuck.

The Zoeller M53 sump pump has a thermoplastic impeller that is reinforced with a piece of metal inside of it. Since it is plastic, it won’t rust. The downside is that the plastic can be worn away by sand, clay particles and other bits of grit. Such as hard water minerals like calcium and magnesium.

Many sump pits are not installed so as to prevent small rocks from getting into the sump basin. Once in the basin the sump pump will try to pump the rocks out with the water. Smaller rocks can damage a plastic impeller and larger ones may get jammed in the pump.

If the impeller can’t turn, then it can’t pump any water either. Also, a jammed impeller will cause the sump pump motor to overheat. If the problem isn’t fixed immediately the pump will need to be replaced.

Also, it is not uncommon for iron bacteria to create a thick red, brown, or yellow slime. The slime sticks to everything and can plug up the sump pump.

Iron bacteria slime can be brushed or scraped off but chemicals are easier to use. However, all methods of removal are more likely to damage the plastic impeller than the cast iron impeller.

The impeller on the Zoeller M57 sump pump is made of cast iron and it is rare that any rust forms on it. That is probably because of all of the grit polishing the impeller as the pump is working. No, the cast iron impeller will not wear away. The motor will die of old age before the impeller fails.

Cast Iron or Plastic Base Material and Pump Weight

The cast iron base of the Zoeller M57 sump pump is about six pounds heavier than the M53 model which is made of plastic.

The plus side of the cast iron base is that it won’t tend to move around in the sump basin as the pump runs. One of the most common problems with sump pumps is that the float ball gets pinched against the sump basin or tangled in the power cords. How? It is all because the sump pump moved while pumping water.

When lowering the sump pump into the sump basin, those six pounds could mean a lot. The M57 weighs 29 pounds all by itself. However, you need to add the discharge pipe to the pump and the backup pump if using one (I do). Factor in that all of this is rather unwieldy. So, can you lift, carry, stoop, and place that much weight without hurting your back? Maybe the lighter weight Zoeller M53 sump pump is a better choice for you.

I have already mentioned that the Zoeller M57 weighs an additional six pounds (2.7 kilograms) more than the Zoeller M53 model.

Cost vs Value and Peace of Mind

If your budget is tight, then get the Zoeller M53 sump pump. 

I have already said that the Zoeller M53 vs M57 price difference is $43 (at time of writing). What you get are fewer potential problems because of the cast iron vs plastic parts. For me, the fewer times I have to get out of bed or drive home for an emergency pump fix the better.

Zoeller M53 vs M57 Features That Customers Want

As I have said, both pumps have identical features that are important to customers. These are some of the reasons for buying these two sump pumps.

Cast-Iron Pump Housings Are Better Than Competitor’s Plastic Housings

When the sump pump is running constantly, the heat that the motor creates must be removed or the motor will burn out. That means buying a new sump pump.

So, I prefer the cast iron pump housings because they can pull the heat away from the motor and release it into the water in the sump basin. Sure, plastic housings do the same thing but not nearly as well. Which leads to another problem with plastic pump housings – cracks.

When a plastic sump pump housing isn’t able to dissipate the heat from the motor fast enough the plastic housing will crack. That of course lets water into the motor and ruins it.

The second benefit of cast iron sump pumps is their weight. Every sump pump will vibrate while running. That vibration can make the sump pump slide around in the sump basin. When that happens the float switch mechanisms can get pinched and prevent the pump from turning on or off. Cast iron pumps are much more stable than plastic sump pumps, which greatly lessens the chances of the pump failing.

Also, sump pumps made of stainless steel or aluminum are better than plastic but they are still lighter weight than the cast iron Zoeller sump pumps.

Zoeller M53 and M57 Float Switch and Float Ball

Both pumps have a two-pole mechanical float switch. That’s the technical term. Simply stated, a solid float ball slides up and down on a plastic rod. The bottom of the plastic rod is attached to the sump pump housing by a metal strap that holds the bottom of the rod in place. The top of the plastic rod is attached to the stainless-steel rod that activates the switch inside of the sump pump.

This is a very reliable switch system. Since the plastic rod is attached at its bottom end the float ball cannot move out of place and get stuck like tethered cord floats can.

The minor downside of the float switch system is that it has a smaller operating range and cannot be adjusted. The end result is that somewhat less water is pumped out between on/off cycles than is possible with a corded tether switch. However, corded tether switches get tangled in power cords or pushed against the sump basin, which stops it from working.

So, the pump turns on at a water depth of 7-1/4” (18 cm) and off at 3” (8 cm). Which is less than is possible with a corded tether switch but without its problems.

Another advantage of the Zoeller float switch system is that other competitors do not attach the bottom of the float rod. Those rods are made of metal but they tend to wobble a bit as the pump runs, which creates a slightly greater chance of the float ball not moving properly.

Also, at the top of the pumps there is a stainless-steel metal loop that helps preventing the float ball from being obstructed by power cords etc.

The Zoeller M53 and M57 Electric Motor

Zoeller Pump company designs their pumps to normally work at 80% of the pump’s capacity. Part of that design is that motors are 1/3 HP and run at only 1550 RPMs which is slower than some other motors. Which means that they are not being worked hard all the time like some other brands might do. This is a plus when the pump is running nonstop for days or if the impeller gets momentarily stuck for some reason.

Also, the pumps have an automatic reset thermal overload protection built in to prevent the motor from burning out if the impeller gets jammed up with a rock.

Should I Buy The Zoeller M63 vs M53?

An even better upgrade is the Zoeller M63. See my article: The Zoeller M53 vs M63 Differences Reviewed: Pros and Cons

The Last Word on The Zoeller M53 vs M57 Sump Pump Question

I prefer the Zoeller M57 sump pump for its all cast iron construction but it isn’t what most people buy. Five times more people buy the Zoeller M53 vs M57. I guess they just want to save a few bucks, because both pumps are well worth the price.