Have you experienced this before? You fill your Berkey up, and the next thing you know, water is pouring out from between the upper and lower chamber. Fear not! You’re not alone.
This is actually normal. It is physics actually. For a gravity system to work, water has to move from the upper chamber to the lower chamber through the filters. When it does, it has to go somewhere. Which means all of the air that is in the lower chamber has to go elsewhere to allow the water to come in. The system is designed to allow some air to leave from in between the upper and lower chamber. Thus, it is not a sealed system.
If the system were sealed, you would run into two issues. First, water wouldn’t have anywhere to go as it moved from the upper chamber to the lower chamber. So nothing would filter. But second, if it is sealed, you would also find that when you open the spigot to pour water out, nothing would come out. Or the flow would be very low. That’s what is known as vapor lock. The water won’t come out of the spigot because if it does, it would create a vacuum in the lower chamber. The pressure of the vacuum holds the water in the lower chamber and prevents it from leaving. It is just like the little trick you can do with a straw in a glass. Put the straw in the drink, put your finger over the top of the straw, and then lift up. The liquid stays in the straw until you move your finger off the top of the straw. Your Berkey functions the same way.
So, some tips for proper use. First, in a normal system, this means that because the system is NOT sealed, then when you put water in the top, it will move to the bottom. So…if your lower chamber is already full, and you fill up your upper chamber, then the water will go somewhere. It will come out the small gap between the two chambers and it WILL overflow onto your counters and floor. That part is normal. What isn’t normal is filling up your Berkey that much.
You need to remember to never put more water in the upper chamber than you have space for it in the lower chamber. If your lower chamber is empty, you can fill up your upper chamber. If you lower chamber is half full, you can fill the upper chamber half full. But if you lower chamber is already full…then do NOT add more water to the upper chamber. Tip: if you want to know how much water is in your lower chamber at any given point, an easy way is to use a water view spigot. We sell two types of Berkey water view spigots. The original water view spigot as well as the Berkey stainless water view spigot.
So next tip…if you open your spigot and no water comes out, but there is water in the lower chamber, then you have vapor lock going on. Your upper and lower chamber are fitting together too snugly. You can know for sure this is happening by opening up your spigot (with a glass to catch the water), and then lifting your upper chamber off the lower chamber. If water flows faster when you do this, and slower when it is resting together, then you know this is the issue.
To solve this, you can use the vapor lock clip which comes as part of the Berkey optional accessory kit. We include those now with new units, but those are not included with blemished or refurbished units. If you need one, you can buy that kit here. You slip the clip over the edge of the lower chamber and it creates a small gap for air to enter and exit. Problem solved.
Two other ways you can solve this without having to buy the kit. The first would be to press on the opening of the lower chamber (squeeze it) to ever-so-slightly deform it. It only needs to bend a little. You just need it to not perfectly mesh up with the bottom of the upper chamber. You won’t be able to visually see any difference, so we’re not talking about a large deformation.
Another inexpensive option would be to just rest an unfolded paper clip over the lip of the lower chamber. It doesn’t look as pretty as the vapor lock clip, but it works.
Hopefully these tips help you keep your Berkey flowing, but not overflowing!
