my APEC water system tank seems to have very low pressure, barely any water comes out of the faucet. how do I check it?

Diagnosis

The APEC ROES-50 utilizes a pressurized storage tank containing a food-grade rubber bladder that separates the purified water from a cushion of compressed air. This air pressure is what pushes the water up through the tubing and out of your faucet. When you experience a "trickle" or very low flow, it is almost always because the air bladder has lost its pre-charge pressure over time or has developed a slow leak. Without sufficient air pressure, the water cannot be displaced from the tank, even if the tank is physically full of water.

To confirm this is the issue, perform a "weight test." Lift the tank or try to tilt it. If the tank feels incredibly heavy (like it's full of water) but only a few ounces of water come out of the faucet, the bladder has lost its charge. If you open the faucet and it flows strongly for two seconds and then dies completely, the tank is likely empty and the RO membrane is the problem. However, if the flow is consistently weak and slow despite the tank feeling heavy, the air pressure is the root cause.

How to Fix It

To restore the pressure in your ROES-50 tank, you will need a low-pressure tire gauge (capable of reading 0-60 psi) and a manual bicycle pump or a small compressor with a regulator.

1. Isolate the Tank: Locate the blue plastic valve on top of the storage tank. Turn the valve 90 degrees to the "off" position to shut off the water flow from the system to the tank.
2. Drain the Tank: Open the RO faucet on your countertop. Let the water run until the flow stops completely. To ensure the tank is 100% empty, keep the faucet open while you perform the next steps. If water continues to drip, the tank is not fully drained.
3. Locate the Air Valve: Find the Schrader valve (the same type found on car tires). It is typically located on the side or bottom of the tank, often protected by a small plastic cap. Remove the cap.
4. Measure Current Pressure: Press the tire gauge firmly onto the valve. For an empty tank, the reading should be between 7 and 8 psi. If it reads 0-3 psi, the tank is under-pressurized.
5. Inflate the Bladder: Using your pump, add air in short bursts. Check the pressure frequently. You must reach exactly 7-8 psi. Do not exceed 10 psi, as over-pressurizing will reduce the actual volume of water the tank can hold.
6. Restore Service: Once 7-8 psi is achieved, close the RO faucet and turn the blue tank valve back to the "on" position. Allow the system to refill (this may take several hours) before testing the flow again.

If That Didn't Work

• Check for a Ruptured Bladder: While pressing the Schrader valve pin with a small screwdriver or nail, look at what comes out. If water squirts out of the air valve instead of air, the internal rubber bladder has ruptured. The tank is permanently damaged and must be replaced with a new APEC compatible storage tank.
• Inspect the RO Membrane: If the tank was empty and the pressure was correct, but it refuses to refill, your RO membrane (the large center canister) may be fouled or clogged. Check the waste-water line; if no water is flowing to the drain, the membrane is likely blocked.
• Verify the Auto-Shutoff Valve (ASO): If the system never stops making noise or the tank never fills, the ASO valve may be stuck. This prevents the system from building the back-pressure needed to stop the water feed, leading to an inefficient fill cycle.
• Check the Faucet Aerator: Occasionally, the low flow is not a pressure issue but a clog in the faucet head. Unscrew the small aerator screen at the tip of the RO faucet and check for calcium buildup or debris.

Heads Up

• Never Pressurize a Full Tank: Adding air while the tank is full of water can cause the bladder to rupture or create dangerous internal pressure. Always drain the tank completely before using a pump.
• Avoid High-Pressure Compressors: Do not use a heavy-duty automotive compressor. These can jump from 0 to 30 psi in a split second, which can blow out the bladder. A manual bicycle pump is the safest tool for this job.
• Annual Maintenance: Air pressure naturally migrates through the bladder walls over time. It is a good practice to check and top off the tank pressure every 12 months during your filter changes.
• Temperature Sensitivity: In very cold garages or basements, air pressure will drop naturally. If your system is in an unheated area, you may need to adjust the pressure more frequently.