Why is the Air Gap in My RO Faucet Leaking?

An air gap creates a gap between the contaminants filtered from your RO system and the clean, filtered water and system. If there was a back flow from a clogged drain pipe, the contaminated water would flow back into the RO system, damaging the filters. Instead, the air gap sends the water back through the drain lines. But sometimes certain situations can cause water to back up and leak out of the air gap. These situations can include clogged or kinked drain lines, improper installation, a loose or shifted drain saddle, system wear and tear, or high water pressure rates. Let’s explore some of these issues and what you can do to correct them.

A typical RO air gap faucet has three lines: the filtered water line, a line connected to the brine output, and a line carrying the wastewater from the faucet air gap to the drain saddle. It is this third, 3/8” wastewater line connected to the drain saddle that is often the reason for air gap leaks.

First, you should make sure that the connections for this tubing are correctly installed. If there are kinks or loops in the line, it can cause water to push back up into the air gap and leak. Dips and low spots in the line that are below the drain saddle can give the same result. Correct the issue by disconnecting the line and reconnecting it without kinks, loops, or dips. If needed, shorten the line first.

Overtime, debris can gather in the 3/8” drain line causing clogs. As a result, back pressure will push water through the air gap. To correct the problem, use a wire brush, pipe cleaner, or similar to clear the debris from the line. Disconnect the line from the drain saddle and the faucet, then clean out the entire line.

Check that your drain saddle is clear of debris and is properly aligned. Improper installation of the drain saddle can pinch off the drain line, causing the water to back up to the air gap. In addition, overtime, vibrations from the system and general wear and tear can cause the drain saddle to shift out of place. You can check that the drain saddle is aligned with the drain pipe by inserting a pencil, screwdriver, or similar into the hole.

If the system is new, it may be that the drain saddle was not installed correctly. The drain saddle needs to be installed above the p-trap and as far away from the garbage disposal and dishwasher drain hose as possible. If it is in the wrong position, you will need to remove and reposition the drain saddle, making sure to replace the pipe where the saddle was previously installed.

RO systems and any water system or filter will usually list a recommended pressure range. If the water pressure exceeds this range, it can result in damage to the connectors, tubing, or drain saddle that can result in air gap leaks. High pressure may also cause damage to the pre-filters and RO membrane, so making sure that your water pressure is within the rating can help save your system overall. If you are having problems with high water pressure or with sudden spikes in pressure, you may want to install a pressure regulator.

Reverse osmosis systems generally have a life expectancy of up to 15 years depending upon a number of factors, such as amount of use, proper maintenance, and others. Unfortunately, if your system is getting older, the only real solution would be replacement.

If your system is still under 8 years of age, you can check that the connections are still intact and haven’t loosened over time. You can also ensure that the faucet stem hasn’t been damaged, which can also result in air gap leaks. If the faucet stem has been damaged, replacing the faucet is usually the best solution.

While a leak from your air gap does indicate that it is working as designed to protect your system, the actual leaking can be a nuisance that you will want to try to avoid. First, make sure that your system is properly installed and that the drain line does not have any loops, kinks, or dips. Next, periodically check that all of the connections are tight and not leaking and that the drain saddle is properly aligned and not loose. Finally, avoid flushing chunks of food or other gunk down the drain line to assist in preventing debris build up, along with occasional cleaning of your system and drain line.