Pressure-assisted units differ from standard toilets mostly inside the tank. It's important to know what to do when a certain symptom arises.
These toilets are subject to the same problems as standard toilets—constant running, weak flushes, water leaks—and the repairs are easy.
Low water pressure can cause a problem for a pressure-assisted toilet. These toilets require water pressure between 20 and 80 pounds per square inch (some up to 125 psi) to function properly. If your pressure is too low, check for a clogged whole-house filter element, faulty pressure-reducing valve in the main water line, mineral deposits in a primary or supply valve, or a clogged supply line or inlet screen. Pipes clogged by rust or minerals may require replacement.
For more potential problems and solutions, see below.
Turn the water off and set a bucket under the supply assembly connection. Remove the supply line from the tank and pull up the assembly to gain access to the screen. Use a bent paper clip to remove the screen and clean off any deposits with an old toothbrush.
On some models it's not necessary to remove the supply assembly to clean the screen. Try making a 1/8-inch right-angle bend in one end of a stiff paper clip. Insert the bent end in a hole near the edge of the screen. Turn the bend so it grabs the screen and pull down gently. The screen should pop out.
With the water supply off, flush the toilet and gently lift up the flush rod. Measure the clearance from the top of the actuator to the bottom of the flush rod. To adjust, loosen the actuator setscrew and raise or lower the actuator by rotating it clockwise or counterclockwise.
Turn the water off to the toilet and flush it by pushing down on the actuator. When the unit begins to flush, carefully raise the actuator to allow debris to be flushed away through the lines.
Replaceable parts vary from model to model. Parts are often available as repair kits or replacement assemblies, such as (A) lower supply assembly with hose, (B) upper supply assembly, and (C) actuator with setscrew.
Proper vertical placement of the actuator is crucial to the operation of a pressure-assisted toilet. A built-in device allows you to position a replacement accurately. Screw the cartridge in until one black line shows. Turn the water supply back on and rotate the actuator clockwise in quarter turns until the water stops. Return the flush rod to its operating position.
Checking the actuator requires removing it, which means shutting off the water, moving the flush rod out of the way, and loosening the setscrew. To move the flush rod, disconnect it from the flush handle and lift it up and away from the actuator.
Loosen the actuator setscrew and slide the rubber-coated handles of a pair of slip-joint pliers into the recesses at the top. Unscrew the actuator (counterclockwise) until you can pull it free.
Pull out the actuator and inspect the O-rings for any damage. If they're worn, replace the actuator. Install the new cartridge (or replace the old one) by turning it clockwise. Turn the water back on and, if it still runs after it's full, tighten or loosen the actuator in quarter turns until it stops.
To check the air regulator (air inducer), remove the muffler cap and flush the toilet. You should hear the sound of air being drawn in. You also can place a couple of drops of water on the hole in the cap and flush the toilet. The water should be drawn into the cap. If it doesn't, go to Step 2.
The duck-bill valve is inside the air regulator. If it gets clogged with mineral deposits, it prevents the air regulator from working properly. Remove the cap and the valve and clean the valve parts with a soft toothbrush.
To check the flush-valve cartridge for leaks, pour a small amount of water into the cartridge housing area. If bubbles form at the center or the edge of the cartridge, replace it. If the vacuum breaker is leaking, it is likely that the water pressure is insufficient or the inlet-screen in the supply assembly is plugged.