Why Your APEC Reverse Osmosis System Is Leaking – And How To Fix It


Reverse Osmosis systems such as the APEC water system have many different parts, and as such there is a wide range of possible reasons why your APEC water system may be leaking.

APEC reverse osmosis system leak due to the high internal pressure causing the fittings to buckle and leak with age. Other common APEC leakage problems involve broken or faulty O-Rings, clogged drains creating an air gap leak, and pressure spikes.

To find out more about what could be causing your APEC water system to leak, how long your APEC water system should take to drain, and more importantly how to solve any leaks or drainage issues, read on below.

Many of the leakage problems explored in this article are also applicable to other RO (Reverse Osmosis) systems due to the similarities across brands.

Pressure & Fittings

RO systems such as the APEC water system work through maintaining a high air and water pressure to push your tap water through the membrane that removes any harmful or unwanted contaminants. The correct pressure is also important for pushing your filtered water back out of your tank and up to your faucet.

Because RO systems depend on being highly pressurized, any connecting fittings are susceptible to buckling under the pressure of the system. This usually occurs after a significant passage of time – the pressure simply wearing down the system, though it can also occur early on in an APEC water system’s lifetime.

This typically occurs when your municipal water supply increases in water pressure, which can happen from time to time. Because the APEC water system is linked directly to your tap water system, an increase in pressure in the municipal water supply can increase the pressure in your RO system.

Pressure damage most often leads to burst fittings where the high pressure has loosened or broken the connection fittings – these should be easily identifiable as you will be able to see and feel the water leaking from that area.

If this is the issue, you can first try detaching and then reattaching the connector fitting if it has simply been loosened.

If the connector fitting has been seriously damaged, you can buy a replacement on the APEC water website or from the APEC Amazon store.

Leaking Faucets

The APEC water system, along with all other RO systems, have an air gap which is vital for stopping the backflow of water into the RO unit, and directing excess water into the drain lines.

You can quickly identify if there is an air gap leak if water is pouring out from the air gap hole at the base of your faucet.

This can happen for one of two reasons. An air gap leak can occur if the drain line tube is not straight enough leading to the drain saddle connection – any loops or significant sharp dips in the drain line can cause the water pressure to push past the air gap, causing a leak.

Equally, any debris or solids clogging up the drain line can also cause the same issue, pushing water up past the air gap and leaking out the air gap hole.

Both issues have a relatively simple fix:

  • For clogged drain lines simply disconnect the drain line and unclog it manually, and then reconnect.
  • If the drain line has loops or sharp dips disconnect the drain line and straighten the tube out before reconnecting.

Leaking Filter Houses

A leak from the filter/membrane housing is almost always caused be problems with housing’s O-Ring. The O-Ring is common in almost all water filtration and other plumbing appliances and is a small ring of rubber designed to create an air-tight seal between interlocking components.

If the O-Ring is damaged or twisted, water will leak from the seal between the housing and the connector tubes. To check the condition of your O-Ring, you will need to:

  • First, close off the system’s feed valve to prevent any more water flowing through while you work.
  • Second, close the RO tank valve for the same reason, and to do this you simply turn the tank ball valve, which is a blue cap on the tank, 90 degrees.

It is possible that the O-Ring has simply been twisted or pushed out of place – this is a common problem if you regularly service your APEC water system (or any other RO system) and repeatedly interact with the connection.

If the O-Ring is not damaged, you can very easily push the rubber band back into place so that it fits smoothly around the hosing entrance – this is the case for any reverse osmosis system.

In the event that the O-Ring has snapped or is otherwise damaged, which can happen in older APEC water systems (usually when they are more than ten years old), you can order a replacement O-ring that suits your model from the APEC website here or from the APEC Amazon store.

It is important that you ensure you have the correct O-Ring for your specific make of APEC water system, as the size and shape of the ring can vary for different APEC models.

For other RO systems made by other companies, your best bet it to check the website of your brand for any available O-Ring replacement packs.

It also never hurts to contact your respective provider’s customer service to see if they may provide a free replacement!

If the filter housing is still leaking after fixing and/or replacing the O-Ring, the most likely cause is that the casing is damaged beyond repair, which means you will need to replace the filter as you would if the membrane had stopped working. APEC water filter replacements are available on their Amazon Store.

Ways to Prevent Leaking

One of the reasons the APEC water system, and indeed reverse osmosis systems in general are so popular, is the fact that they are designed to have extremely long lives compared to other water filtration options on the market.

The best way to stop leaking in your APEC water system is to regularly clean and service it, extending its life and reducing the chance of parts taking enough wear and tear to create leaks.

The first parts of the APEC water system to wear down are the filter membranes. It is not only important to replace these regularly to ensure you receive clean water, but also to prevent wear and tear on the overall system, as the less water with high TDS (Total Dissolved Solids) moving through your system, the better.

To find out how often to replace each filter part on your APEC water system, check APEC water’s table on maintenance on their FAQS, as this provides a clear breakdown of each filter part for every version of the APEC reverse osmosis water system they sell.

Along with replacing the filters, you should aim to check the entirety of your APEC water system or other RO systems every six months. This includes checking:

  • The drain line regularly for debris and cleaning it out
  • The air pressure in your tanks, and
  • The connection fittings for all the different components of your APEC water system.

Make sure all the connection fittings are secure and tight, though be careful not to overtighten as this could twist and misshape the O-Ring.

If you would rather have a professional check your system, APEC offers repair and servicing assistance (for a small fee). Simply call them at 626-600-9636 to sort out having a professional coming round to service your APEC water system.

Because of the complexity of reverse osmosis systems, there are plenty of available add-ons you can find to improve your system. Be sure to check out our article on 16 ways to improve your RO system to find out more!

Drainage Issues

APEC water systems should typically take 1.7 to 3 hours to drain as your tap water is separated into filtered water that goes into the tank, and wastewater that goes down the drain.

Along with leaks, another common problem with APEC water systems and other RO systems is constant drainage.

Not only does constant drainage waste your water, racking up your utility bills, but it can also sometimes be loud and annoying.

Constant drainage will be most often caused by a low pressure from the feed water. This needs to be at least 45 psi for reverse osmosis to work, as any less pressure and the feed water cannot be pushed through the small pores in the filter membrane. This results in all your water going directly into the drain.

To check the psi, simply look at the feed water valve. If the tap water pressure in your area is too low and is not a temporary issue (pressure can fluctuate due to seasonal temperature and other variables) you can purchase specialized APEC RO pump systems that will create enough pressure for the reverse osmosis system to work.

Constant drainage can also occur if your membrane filter has been worn down and needs to be replaced.

The other possible reason your RO system could be constantly draining is a faulty ASO valve (Automatic Shut-Off valve) or check valve. The ASO is designed to close when tank pressure reaches 2/3 of supply line pressure – this will not happen if the ASO is stuck or the check valve is leaking pressure, preventing the ASO from closing.

The ASO is usually the cause of the problem and will need replacing if it is faulty.

To check if the problem lies with the check valve, you will need to have a full tank of water and leave the tank valve open. If you turn the water supply off and water still flows to the drain, the check valve is at fault, and you will need a replacement. If your RO system is not APEC, you will need to find specific replacements for your brand of RO system.

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