Upflush Toilet Problems and How to Fix Them

An upflush toilet is a toilet with a macerator embedded in a small compact tank that sits on the space behind the toilet bowl. The macerator contains a small cutting blade that automatically activates once you pull the flushing lever. The blade’s rotation usually transforms solid waste materials into a uniform liquid slurry. Ultimately, the pump adjacent to the macerator discharges the waste, and the tank empties in readiness for its subsequent use. Despite the multiple upflush toilet problems experienced by some users, they also have wide-ranging advantages.

One such benefit relates to the toilet’s installation flexibility. In essence, you can install your new upflush toilet anywhere, including the attic and the basement. Additionally, upflush toilets are cheap to install and maintain. Lastly, these toilets are easily movable and can occupy the same floor space as a regular one-piece or two piece toilet.

Common Upflush Toilet Problems and How to Solve Them

When you decide to purchase an upflush toilet, you must know that you will likely encounter a raft of problems. This guide highlights the issues and the probable solutions to the challenges.

Foul Smell

Upflush toilets can develop a foul smell, mainly when used for a while. It is worth noting that limescale can develop in the macerator tank after a certain period. Since the macerator tank has little water quantities at any given time, limescale can combine with solid waste to produce an unpleasant smell.


Occasionally descaling your upflush toilet will solve this problem. In essence, you should read the toilet’s user manual to help you conduct proper descaling. The most common procedure for descaling your upflush unit entails filling the macerator tank with white vinegar and leaving it for about 120 minutes before flushing the toilet.


Another common problem that afflicts upflush toilets is clogging. Notably, upflush lavatories are susceptible to clogging because they are only equipped to handle toilet paper, human waste, and urine. If anything else finds its way into the macerator tank, it will inevitably clog up. The macerator pump can also get stuck in the process. If either the macerator shredder or the pump malfunction, the toilet can flush repeatedly, and it may be difficult to stop it.

Additionally, debris can clog the tank’s discharge pipe, prompting the pump to operate unceasingly without necessarily emptying the macerator tank. In bathrooms where the user employs the upflush toilet to drain other bathroom accessories, you can tell that the tank is clogged when wastewater emerges from the drains.

Soaking clogged toilet
Soaking clogged toilet


Feasible solutions to the clogging problem are dependent on the cause of the blockage. The solutions may include:

  • You can purchase an upflush unit that includes a grader in the macerator. Essentially, the grader is equipped to shred hard items that may accidentally clog up your toilet system.
  • If the toilet flushes repeatedly, the best solution is to unplug the toilet unit, lift the lid of the macerator tank and manually remove the foreign objects with tongs or pliers. If the foreign debris is in the pump, you have to remove the pump entirely for inspection and servicing.
  • If the debris is stuck in the tank’s discharge pipe, it is advisable to seek the services of a plumber. Notably, significantly low temperatures can also cause blockage in the tank’s discharge pipe. In such instances, you should wait for daily temperatures to rise.
  • Lastly, you should check if the toilet’s power outlet has tripped if the pump suddenly stops functioning and wastewater flows back out of your bathroom drains.

Excessive Vibration and Noise

Violent vibration and noise is a problem that is common in upflush toilets. Notably, the problem is caused by disintegrable foreign debris that impedes the macerator blade’s rotation.


First, you should cut off the pump’s power supply by unplugging the power cable. Next, you should remove the lid of the macerator tank and take a look. After examining the macerator, clear it if it is blocked. In essence, you should use thin-nosed pliers to turn the macerator blade counterclockwise and remove the foreign object in the process.

The Macerator Pump Keeps Firing at Random Intervals

As the owner of an upflush toilet, you might encounter a problem where the macerator pump keeps starting at random intervals. It is worth noting that a faulty power supply system or micro-switch is often the root cause of this problem. More specifically, the round rubber membrane responsible for activating the switch could be dysfunctional.  When the membrane suffers damage, waste enters the micro-switch and interferes with its normal functioning.


A micro-switch can become dysfunctional when debris gets stuck between the floor of the macerator tank and the micro-switch. This situation causes the micro-switch to operate the same way it works when the macerator tank is filled and requires flushing. So first, clear the tank and remove any debris wedged close to the micro-switch to solve the problem. After that, restart the macerator pump to check it is functioning normally.

If the round rubber membrane appears damaged, you should consider replacing it with the micro-switch.

The Macerator Pump Foaming from the Vent

Another common problem with upflush toilets is the macerator foaming from the air vent. If you encounter the scenario, you should know that it is predominantly caused by cleaning detergents and bleach.


The first thing you should do is replace the membrane that shields the micro-switch. It is worth noting that as the rubber undergoes wear and tear over time, the membrane becomes loose. Therefore, if the solution is ineffective, you should replace the entire micro-switch.

Frequently Asked Questions (FAQs)

Are upflush toilet toilets durable?

Today, most upflush toilets available in the marketplace are significantly durable, with the warranty given by brands dealing in upflush toilets averaging ten years.

Does an upflush toilet require additional space on a bathroom floor?

Not necessarily. On average, an upflush toilet takes up the same floor space as a regular toilet because the macerator tank is positioned behind the toilet bowl.

Does an upflush toilet emit a smell?

An upflush toilet is more likely to emit a foul smell than a regular toilet and requires occasional cleaning and maintenance.

Wrapping Up

Hopefully, this guide has helped you understand your upflush toilet better and equipped you with the know-how to address various upflush toilet problems that could crop up from time to time. Please feel free to share your experiences with us in the comment box below.


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