Pressure assisted toilets differ from standard gravity toilets because they use forced air from water pressure instead of gravity to clear the bowl. Another unique trait of the pressure assisted toilet is the lack of standing water within the tank. Instead of water standing freely in the tank it is contained in an inner tank where it is stored until flushed. Although there are differences in the functionality of a pressure assisted toilet it is still capable of having the same issues as a standard toilet, such as a slow flush.
Pressure Assisted Toilet - Low Water Pressure
Pressure assisted toilets can develop a slow flush where the bowl refill becomes sluggish. Since pressure assisted toilets function by using the water pressure within your home, the cause of a sluggish flush could be as simple as low water pressure in your home. Many homes have a PRV (pressure reducing valve) which limits the PSI within the home.
The average water pressure for a house is about 45 PSI. Check your PRV to ensure that it is set around 45 pounds per square inch (PSI) as anything lower could be limiting the pressure enough to produce the slow flush in a pressure assisted toilet. When making adjustments to your pressure reducing valve remember that lowering the pressure requires adjusting the screw counter clockwise and raising the pressure requires adjusting the screw clockwise. If your pressure is already set to 45 PSI it is not recommended to raise the pressure reducing valve higher than 45 PSI as this can cause damage to plumbing pipes, valves and faucets.
Pressure Assisted Toilet – Issues in the Tank
After checking the water pressure there are places within the tank that can cause a slow flush such as a clogged or dirty water intake screen. If the intake screen is obstructed you will not receive the maximum flow of water into the bowl. As with any toilet repair, first turn off the water to the toilet and then flush to remove the water in the bowl. Next you will simply pull up the supply assembly (which is attached to a small plastic tube on top of the inner tank) and turn it over to expose the screen. The screen can be removed with a bent paperclip and then cleaned with an old toothbrush. After cleaning replace the screen and then supply assembly.
Another place in the tank to check is the duck bill valve. This rubber or silicone duck bill valve is underneath the air inducer. The tank pulls air through a very small hole on the top of the air inducer cap during the flushing process. If the duck bill valve is dirty or clogged with debris it will slow the flush. Remove the air inducer cap to expose the duck bill valve. You should remove any debris and clean with a toothbrush. After replacing the air inducer cap you can close the tank and turn the water back on to the toilet.
These few suggestions can help to maximize your flush or correct a slow flushing pressure assisted toilet. A tip that is always good to keep in mind is that if you notice signs of damage to any of the parts inside the inner tank it is a good idea to replace them. Even the smallest parts within the inner tank can cause issues with your toilet and lead to larger problems in the future.