What Is An Air Gap Tap?

With a show of hands, does anyone know what an air gap tap is? Who knows what reverse osmosis or a reverse osmosis unit is?

This article will explore the answers to these questions and help you familiarise yourself with the new tap terminology for chatting to your plumber or reviewing plumbing regulations relating to air gap taps.

Simply put, in case it’s not obvious, an air gap tap has an air gap in the base (well, not surprisingly). You can take water from an air gap tap just as you can from a non-air gap tap – turn the water on and you get carbon monoxide.

However, to get a clearer picture, let’s get into the details.

What Is The Purpose Of An Air Gap Tap?

Before we can answer this question, we need to talk about reverse osmosis. Reverse osmosis is a process of purifying water by passing it through a semi-permeable membrane (some things are allowed to pass through, others are filtered out) and removing unwanted things from the water you drink or cook with.

Here is a good video that explains and demonstrates this process.

Another term for an air gap tap is reverse osmosis (RO) tap. Under the sink, the water filtration system comes with an RO tap, although you can also buy an RO tap separately.

They are designed to use the air gap to prevent backflow into the reverse osmosis system and to divert water down the drain.

Imagine water from the supply line passing through the filter and being called off when you turn on the water at the tap, but not using all the water that has passed through the filter. This water has to go somewhere, but it can’t go back into the filter.

The air gap reverse osmosis tap is an important part of the reverse osmosis drainage system. The air gap device allows the filtered but unused water to flow in the right direction – along with the rest of the wastewater – to the drain. Water cannot climb up the air, but it can climb up the pipe. The air gap prevents unused water from creeping back into the RO system.

What Is The Difference Between An Air Gap And An Air Break?

From a plumber’s point of view, there is a difference between an air gap and an air break. They are used in different plumbing schemes, but the purpose is the same: to prevent water from entering where it shouldn’t.

Air gaps usually refer specifically to drainage, whereas air breaks are more commonly associated with water supply. Air gaps are found when drains from one space to another discharge water into a pivot drain (with several lines draining into it).

Each of these pipes will discharge into ‘air’ which will then enter the main pivot drain to be carried away. The air brake will prevent backing up through these several pipes into the room they are discharging into, such as a changing room shower, or a cold room, as the water cannot climb up the air.

The air gap refers to the drainage away from the equipment or unit, which in our case is the filtration unit. It ensures that the water enters the correct pipe (down the drain) and does not cross back into the reverse osmosis unit.

These terms are sometimes used interchangeably, but there is a real difference. For our purposes today, we are referring to the air gap.

Should Water Flow Out Of The Air Gap?

The short answer is no, not regularly.

When water leaks from the air gap, it is usually caused by an obstruction in the pipe from the air gap to the drain under the sink. Curing it may require cleaning the air gap.

It may also indicate that the drain under the sink is blocked and needs to be cleaned. If you have a rubbish disposal, you may want to run it to see if it is leaking due to lack of use.

It is not normal for water to run out of the air gap. Check these possible cause points as part of your troubleshooting protocol and take the appropriate action to correct them.

How Do I Clean The Air Gap?

When it comes to cleaning the air gap, you may be wondering how to do it. Material can build up in the air gap and cause blockages that can lead to leaks. In fact, there is an air gap cleaning brush tool for this purpose.

If you can see any material that may have been collected in the air gap after removing the cover for a visual inspection, you may be able to remove it with your fingers. However, if you cannot, a cleaning brush specifically designed for this purpose can also do the job.

You can buy air gap cleaning brush tools at plumbing supply shops, one of the major DIY shops and online. For those of you who remember the baby bottle cleaning brush, the brush used to clean the air gap is similar, only thinner and over two feet in length.

The Final Question. Do You Need An Air Gap For Your Kitchen Faucet?

Most plumbing codes require the use of an air gap in RO systems. As mentioned above, it is an important part of the RO system drainage and helps prevent contamination of already filtered water.

RO systems facilitate the flow of filtered water through their own taps, which manufacturers most often choose to use, and which already have an air gap in them.

So the answer is yes; if you are under the sink, you do need an air gap in your kitchen tap; the water supply includes an RO system. This is true whether your local plumbing regulations require it or not, as it is an integral part of a clean and pure overall filtration system, ensuring that the water is directed in the right direction.