Diagnosis
The issue you are experiencing—where the system delivers a small burst of water and then shuts off, causing the pump to cycle frequently—is a classic symptom of "air-locking" or an incorrect pre-charge pressure in the storage tank's internal bladder. The Frizzlife PD600-TAM3 uses a pressurized diaphragm tank to push water out to the faucet. If the air pressure in the bladder is too high, it creates a physical barrier that prevents the RO membrane from filling the tank beyond a few cups of water. Because the tank is technically "full" (due to the high air pressure compressing the remaining space), the high-pressure switch triggers the pump to shut off. However, as soon as you pour a half-glass of water, the pressure drops instantly, triggering the pump to kick back on. This "short-cycling" is inefficient and can lead to premature pump failure if not corrected. You can confirm this by weighing the tank; if it feels light despite the pump running, the water is not actually entering the bladder.
How to Fix It
To resolve this, you must calibrate the air pressure of the storage tank while it is completely devoid of water. Follow these exact steps:
- Turn off the main feed water supply valve to the system.
- Open the RO faucet and let all the water drain out completely. Keep the faucet open until no more water drips out.
- Locate the air valve (Schrader valve) on the top or side of the blue storage tank. Remove the plastic cap.
- Use a low-pressure digital tire gauge to measure the current PSI. For the PD600-TAM3, the empty tank pre-charge must be exactly between 6 and 8 PSI.
- If the pressure is too high: Gently press the center pin of the valve stem with a small screwdriver to bleed air until the gauge reads 7 PSI.
- If the pressure is too low: Use a standard bicycle pump or a small air compressor to add air in short bursts. Check the gauge frequently to avoid over-pressurizing.
- Once you hit 7 PSI, replace the valve cap securely.
- Close the RO faucet and turn the feed water supply back on.
- Allow the system to run for 2-4 hours to fully recharge the tank before testing the flow rate again.
If That Didn't Work
- Check the Auto-Shut Off Valve (ASO): If the pump continues to cycle even after the tank is pressurized, the ASO valve may be stuck or leaking. Inspect the small 1/4" tubing connecting the membrane housing to the ASO valve for kinks or leaks. A leak here will trick the system into thinking the tank is never full.
- Inspect the Check Valve: There is a one-way check valve located at the exit of the membrane housing. If this valve is faulty, water will flow backward from the tank into the membrane, causing the pump to trigger every few minutes to "top off" the tank. Replace the check valve if you hear a clicking sound coming from the membrane housing.
- Verify Pump Power Supply: Ensure the power adapter is plugged directly into a wall outlet and not a crowded power strip. Voltage drops can cause the pump's internal pressure switch to trip prematurely, mimicking a full tank.
- Replace the Tank Bladder: If you add air to the tank and it leaks out within 24 hours, or if water squirts out of the air valve when you press the pin, the internal rubber diaphragm has ruptured. In this case, the tank cannot be repaired and must be replaced with a compatible 3.2 gallon RO tank.
Heads Up
- Never use a high-pressure automotive compressor to fill the tank; it is very easy to overshoot 8 PSI, which will either lock the tank or rupture the bladder.
- Check your tank air pressure every 6 months. It is normal for these tanks to lose a small amount of air over time, which leads to slower flow rates.
- When replacing filters, always open the faucet for 30 seconds to release trapped air before restarting the pump to prevent "air hammering" in the lines.
- Ensure the tank is sitting level on the floor; tilting the tank can cause the internal bladder to shift, leading to inconsistent pressure readings.