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Air gap faucets are commonly used with reverse osmosis systems for their ability to prevent wastewater backflow into the RO membrane.
While they work well at this, they tend to clog up and leak – so you’ll want to familiarize yourself with their operation and potential leak causes.
Let’s take a look at some of the most common reasons for why a reverse osmosis faucet could be leaking from its air gap, and how you can fix these issues yourself.
An air gap RO faucet is a faucet with built-in backflow protection to prevent wastewater from flowing back into the filter system should the sink drain pipe become clogged. Air gap faucets are often sold with RO systems – and are even required by plumbing codes in some municipalities.
Unlike a regular reverse osmosis faucet – which only has a single connection from the post-filter to the faucet, an air gap faucet has three tubing connections.
There are several reasons your reverse osmosis faucet might be leaking from the air gap.
Of course, the purpose of an air gap RO faucet is to prevent wastewater backflow into the system, so if the faucet is leaking at least you’ll know the air gap is working as intended.
A common reason for water leaking from the air gap is some type of blockage in the drain line. This can happen when a large piece of debris obstructs the flow of water down the line – the water has no other place to go than to flow out of the air gap.
Another possibility is the drain saddle has come loose and is blocking or pinching the drain line. This can block the flow of wastewater down the drain as well – which again will cause water to leak out the air gap.
If you suspect that a clogged drain line is the cause, the first thing to do is disconnect the drain line from both the barb on the faucet and the drain saddle. Then, manually clear the line with a pipe cleaner to break up the obstruction.
If there is no clog in the drain line, then take a look at the drain saddle mounted to the drain pipe. If it’s loose, it can pinch off the drain line causing a clog. Realign the saddle with the hole in the drain pipe and then fasten it tight. You can insert a pen or screwdriver through the saddle and hole to ensure they’re properly aligned.
Another possibility is that the stem attached to the faucet is damaged. Take a look at the stem to check for damage. If this is the case, you’ll need to replace the faucet entirely.
Another common issue is a kink or dip in the drain line. As reverse osmosis systems are fairly low pressure, this can be enough to stop the flow of wastewater and push it to the air gap.
This should be fairly easy to spot by taking a look at the drain line. Obvious kinks in the line are easy to spot, while a dip in the drain line below the drain saddle may not look like a blockage but it can cause backflow toward the air gap.
The obvious solution here is to straighten out the line and remove any possible kinks.
If the drain line dips below the drain saddle, then you’ll want to cut the line shorter so that there is no excess line. Then reattach it and test the flow by turning on the faucet.
Another possibility is that the RO system – specifically the faucet and the drain saddle – was not installed correctly in the first place. This is less likely in the case of a professionally installed system, but a DIY install can lead to all sorts of issues if done incorrectly.
The first thing to examine is the positioning of the drain saddle. Drain saddles should be installed above the P-trap and far away from the dishwasher drain hose and/or garbage disposal. These connections can shoot debris into the drain pipe, which can clog up the RO system’s drain line.
Air gap RO faucets can also be installed or hooked up incorrectly, so you’ll want to take a close look at the faucet and insure it was installed per the manufacturer’s instructions.
If the drain saddle was installed improperly, then you’ll need to remove it and reinstall it in the correct location. This will also require replacing the section of drain pipe where the saddle was previously installed.
If the faucet is improperly installed, then you may need to reinstall it in a new location. If the tubing connections are improperly hooked up, the solution is relatively easy – simply connect the tubing as per the manufacturer’s instructions.
A loose connection somewhere in your RO system is another cause of your RO system leaking. This typically happens to newly installed units, as it’s fairly easy to install a tube connection loosely the first time.
This issue can be fairly easy to fix as you might be able to spot the loose connection from the water seeping from it.
Identify the loose connection and tighten it.
Like any other mechanical system, reverse osmosis systems will age and break down over time. The typical RO lifespan is between 8 and 10 years, so if your system is reaching that age there is a good chance that your system will start to form leaks and other problems.
Leaks can form from several different areas, including the air gap in the faucet.
If your reverse osmosis system is reaching the end of its lifespan, the only real solution is replacing the entire system with a new one. Consult your manufacturer’s instructions to confirm the system’s lifespan and replacement schedule.
Occasionally, excessive feed water pressure or spikes in water pressure can cause damage to the connectors, tubing, or drain line. RO systems are designed to work within a certain pressure range for the RO membrane to function correctly so excessive pressure can be an issue for the overall system as well.
If you’re dealing with consistently high internal pressure then you’ll want to consider installing a pressure regulator. This will lower the pressure to the ideal level for your reverse osmosis system to run optimally.
Leaking from the air gap faucet is not necessarily a bad thing – as it’s an indication that the system is working as intended (more or less). However, it’s a bit of a pain to deal with, so you’ll want to take steps to ensure the faucet won’t leak excessively.
There are several precautions you can take in order to reduce to reduce the chance of leaking. Mostly, you want to ensure the system is correctly installed, the connections are tight and not leaking, there are no kinks or dips in the drain line, and there’s no blockage preventing the drain line from flowing.
If you have any questions about your reverse osmosis leaking from the air gap please don’t hesitate to leave a comment below!
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