Pressure Assist Toilet Problems And Solutions Guide.

Although gravity-fed toilets are more popular, more and more people now appreciate the benefits of pressure-assist toilets. They are more efficient, low maintenance, and cleaner. However, make a point of knowing the pressure assist toilet problems should you choose to install one.

Some of the problems you may encounter using a pressure-assist toilet include low water pressure, leaking, continuous running, and explosions.

You can fix these issues by utilizing certain DIY fixes. However, you must troubleshoot the problem first to avoid creating a bigger mess.

Read below for causes and solutions of various pressure assist toilet problems.

How to unclog a pressure assist toilet

Pressure-assist Problems (Causes & Solutions)

The table below shows common problems to expect when handling these dual-tank toilet systems and their recommended fixes.

 ProblemPossible CauseRecommended Fix
1.Problems in the tankDirty or clogged water intake screenClogged duckbill valveClean or replace the water intake screen and duckbill valve.
2.Low water pressureSlow toilet bowl refillLow water pressure in the apartmentCheck the water pressure in your house. Adjust the water pressure in the house.
3.Pressure-assist toilet leakingLoose gasket between the toilet bowl and the tankLoose bolts between the bowl and the tankTighten the gasket and bolts between the bowl and the tank.
4.Toilet keeps runningImproper installation of the flush valve cartridgeClogged inlet screen  Proper installation of the flush valve cartridge Clear the clog on the inlet screen.

1. Problems In The Pressure Tank

Problems in the pressure-assist toilet tank emanate from a dirty and clogged water intake screen and limit the water flow into the toilet bowl. The small amount of water in the bowl denies your fixture the pressure required to flush the waste down the sewer line.

Another culprit behind pressure tank problems is a dirty or clogged silicone or rubber duckbill valve. When dirt or debris blocks the valve, it will lower the toilet’s flushing power and could create additional problems, such as toilet blocking.


  • Cut off the water supply to your toilet.
  • Flush the toilet to drain the water in the bowl.
  • Lift the supply assembly connected to the plastic tube atop the inner tank.
  • Turn the assembly to access the screen.
  • Use a bent paperclip to remove the screen, then clean it with a toothbrush-preferably an old one.
  • Next, replace the screen and the supply assembly.

If the problem sprung from the duckbill valve, follow the steps below to resolve it:

  • Detach the air inducer cap to access the duckbill valve.
  • Clear the dirt or debris and clean the valve with an old toothbrush.
  • Install the air cap back in place and close the toilet tank.
  • Restore the water supply.

2. Low Water Pressure

As the name suggests, pressure-assisted toilets rely on pressure to function optimally, so low water pressure hinders pressure-assisted toilets from functioning optimally. Low water pressure in your apartment will cause a slow bowl refill, culminating in sluggish flushes.

Modern homes have pressure-reducing valves that reduce the pressure in pounds per square inch (PSI). If your pressure-reducing valve reads lower than the recommended value (45), it implies your toilet is a victim of low water pressure.


  • Examine the pressure-reducing valve to ensure it reads 45 PSI.
  • If you need to adjust the valve, turn the screw clockwise to raise the pressure and counterclockwise to reduce it.

NOTE: Experts caution against raising pressure beyond the recommended amount, i.e., 45 PSI. Anything beyond this can damage the valves, faucets, and plumbing pipes.

3. Explosions

Even though pressure-assist toilets employ additional pressure (plus gravity) to flush waste with small amounts of water, pressure can be a problem sometimes. If it goes unchecked, it can damage your toilet by blowing off its top, which could cause severe injuries.

According to Consumer Product Safety Commission reports, these dual-tank systems injured at least 15 individuals and damaged over 300 units.


Get a professional plumber who understands how pressure-assist toilets work to install the toilet for you.

Pressure assist toilet no water

4. Leaking

Like other toilets, pressure-assist fixtures are not immune to leaking. This issue stems from a loose gasket or bolts connecting the bowl and the tank.


  • Close the shutoff valve on your water supply line.
  • Flush the toilet to drain water from the tank and to get rid of the pressure inside your pressure tank. Do this multiple times to drain any residual water.
  • Get hold of the inlet valve and disengage the water line extending to the pressure tank.
  • Remove the water supply tube from the water inlet valve’s tailpiece with pliers, often on the left-bottom corner of the toilet tank.
  • Check behind the toilet bowl and underneath the tank for bolts that hold your toilet in place and remove them using a socket wrench. Alternatively, cut them off using a hacksaw belt.
  • Unscrew the nuts securing the bolts to the tank.
  • Remove the tank and place it aside.
  • Next, clean the area between the bowl and the tank.
  • To install the replacement tank bolts, detach the pressure tank from the toilet tank.
  • Take off the huge plastic anchoring nut from the pressure tank’s tailpiece, which runs through the toilet tank’s base.
  • Apply a rubber washer on the replacement bolts, then insert them through the mounting holes.
  • Install rubber washers on bolts at the base of the tank exterior.
  • Tighten the nuts and press the rubber washers with minimal force to keep the porcelain tank from cracking.
  • If leaking occurs at the joint between the bowl and the tank, replace the gasket.
  • Restore the tank to its original place and insert replacement bolts.
  • Thread nuts and washers onto the toilet tank bolts.
  • Tighten the bolts evenly to secure the tank. Do it as you compress the pressure tank gasket.
  • Reconnect the water supply tube to the water inlet valve reaching the base of the toilet tank.
  • Turn the water back and flush it multiple times to ensure you’ve resolved the problem.

5. Pressure-Assist Toilet Keeps Running

Low water pressure and a clogged inlet screen will lead to a continuously running toilet, thus skyrocketing our water bills. Failure to install the flush valve cartridge will also have the same result.


  • Open the water supply valve fully.
  • Examine the actuator adjustment and ensure the push rod and flush rod don’t interfere with it.
  • Check the inlet screen and clear anything obstructing the flow of water.

How Does a Pressure-Assist Toilet Work?

A pressure-assist toilet (View on Amazon) has an air bladder (black), which compresses when filled with water. It discharges water with considerable force; no wonder they possess great flushing power.

After expelling water, the fill valve opens, allowing water to refill the toilet tank (pressure tank), and the cycle repeats itself.

Are Pressure-Assist Toilets Reliable?

Pressure-assist toilets guarantee up to 30 years of reliable performance with fewer clogging problems, thanks to powerful flushing. Through their lifespan, they can save you around $3500, a feature that makes them ideal for older homes with deteriorated sewage systems.

The manufacturers considered humidity problems when crafting these dual-tank toilets, seeing that they reduce sweat and condensation.

In addition, pressure-assist toilets outclass their gravity counterparts. Even though they rely on gravity, they apply extra pressure, an attribute that causes them to flush the waste down the drain using less water.

These dual-tank systems also require less cleaning and maintenance because the bowl holds more water than other components. It stays clean and spares you the stress of hiring plumbers and the need to use chemicals (which makes them environmentally friendly).

Despite the glowing attributes highlighted above, pressure-assist toilets are not flawless. Homeowners have spent their fortunes getting these toilets owing to their water-efficient capabilities.

The noise from these dual-tank systems is also something to look out for. You may want to block your ears after relieving yourself and want to flush the waste down the drain because of the loud whooshing sound.

Are pressure assist toilets dangerous

How Much Does It Cost to Fix Weak Toilet Pressure?

Excess water in the tank, a leaky flapper, and a faulty refill tube can cost you $50 to $400 to fix and restore the required pressure in your toilet.

Why Does My Pressure Assist Toilet Keep Running?

A blocked inlet screen, an incorrectly set up flush valve cartridge, and low water pressure will cause your two-tank toilet to run continuously.

How Long Do Pressure-assisted Toilets Last?

Low-flow, pressure-assisted toilets can endure 30 years.

Why Is My Water Pressure Low After Flushing Toilet?

After flushing your toilet, the pressure balancing valve takes time to adjust. It diverts the water to refill the toilet tank, resulting in reduced pressure in the water line.

Final Remarks on Pressure-assist Toilet Problems

In summary, pressure-assist toilets are reliable, water-efficient toilets that can serve you for 30 years. However, they have problems, such as leaking, continuous running, slow flushes, issues with the tank, etc.

Go through the procedures discussed here to fix your problems and get your toilet up and running again.

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