You’ve set your CO2 level where you want it – but your keg won’t listen. The pressure keeps creeping further and further up, adding tons of extra foam to every pour. We know how confusing and frustrating this can be. That’s why we’ve dug up the most likely reasons why your kegerator pressure might be rising too high. Take a look below.

The simplest answer is that you’ve over-carbonated your homebrew by trying to force in too much CO2. Or you might have set your regulator before it could cool off, causing the pressure to rise as it sits in the fridge. The regulator could also have debris in the diaphragm or some other mechanical issue. 

You may be able to pull back the pressure with a couple of simple steps. Let’s get to work. 

Glass full of beer foam
If your serving pressure is too high, it can pump excess CO2 into the keg and lead to foaming.

What’s Pushing Up Your Kegerator’s Pressure?

Scenario 1: Your Keg is Over-Carbonated

We’re starting with this possibility for two reasons. First, it’s a common issue. Second, you can skip it if you’re not a homebrewer. Kegs from big commercial breweries are almost never over-carbed. The only exception is if – for some reason – you forced a bunch of CO2 into it after you got it home.

Over-carbonation means there’s more carbon dioxide in your beer than it can hold. It’s escaping from the solution and building up in the headspace of your keg. This drives the pressure higher.

This often happens to brewers who force carbonate by pushing CO2 into the keg at very high pressure. This is a handy trick if you don’t want to wait an extra week or two for your beer to carbonate gradually. But it’s easy to overdo it and add too much gas for your brew to contain.

Another way to get too much pressure in your keg is by letting it warm up after fermenting it at a cooler temperature. The warmer liquid can’t hold as much CO2, so some of it escapes into the headspace of the keg. Bacterial contamination during the brewing process can also generate extra CO2. This will also cause certain kinds of off-flavors in your brew.

Fixing an Over-Carbonated Keg

To reduce the carbonation, detach the beer lines and vent the keg using the pressure relief valve. The Cornelius kegs that homebrewers love don’t always have this valve. If yours doesn’t, push down on the nub on the gas intake port with a screwdriver. 

Rock the keg back and forth several times to knock more CO2 out of the beer. You could also attach your CO2 line to the output fitting on your keg and blast it for about one second. This is a trickier but faster way to force carbon dioxide out of the brew.

Let the keg settle for a couple of minutes, then vent and shake it again. You’ll have to repeat this process at least a few times to get it to a stable level. Check the pressure every so often to make sure you don’t go too far and wind up with flat beer.

Scenario 2: The CO2 Regulator Needs to Cool

Did you put a fresh gas tank and regulator into the fridge, then set it and forget it? This can cause the pressure to creep up over time.

The CO2 regulator has a spring inside that controls how much the valve can open. As it cools down in your kegerator, the metal of the spring contracts. That lets more gas through, boosting the pressure inside your keg.

The difference isn’t huge. If the pressure is more than 5-10 PSI off from where you set it, look for another explanation.

Fixing Temperature Issues in a Regulator

The solution is pretty straightforward. Shut off the CO2 line and vent your keg. Then wait for the regulator to stabilize at the temperature inside the fridge. Once it has cooled off, you can set it to the pressure you want.

Scenario 3: Debris in the Diaphragm

This is the most likely cause if the pressure keeps going up and up to ridiculous levels. Small bits of grit can wedge themselves into the diaphragm of your CO2 regulator. That’s the piece that monitors the pressure to keep it from getting too high. 

The debris prevents the diaphragm from cutting off the gas at the right level. CO2 keeps pouring into your keg, shooting the PSI value absurdly high.

Fixing a Clogged CO2 Regulator

You can sometimes jog loose whatever’s stuck in your regulator with a few bursts of gas. Turn off the CO2 and detach the regulator from the hose leading into the keg. Turn the pressure setting up high, then quickly open and close the valve on your gas tank.

Do this a few times. With luck, you’ll push out the intruding material and free up your regulator to do its job.

If that doesn’t do the trick, you can disassemble your regulator and clean it out. Flush out the crevices with compressed air and soak the parts in sanitizer to get rid of any dust and grime.

Removing CO2 regulator
To remove dust and filth, blow out the crevices with compressed air.

Scenario 4: Busted Regulator

If none of the steps above solved your problem, we’re betting that your CO2 regulator has a broken part. You may notice dents or cracks when you open it up to clean it, though there’s no guarantee the problem will be visible.

In this case, the only thing to do is replace your regulator. This isn’t the cheapest part, but it’s an indispensable piece of your draft system. You need one that’s in working order.

Conclusion

You need to get your keg pressure under control if you don’t want to keep pouring big mugs of foam. Try venting and shaking the keg to correct over-carbonation, then check for issues with the regulator. There’s often a simple fix that will let you rein in the pressure once again.

Thanks for hearing us out! Our site has lots more tips on upkeep for kegerators and other home appliances. For a few examples, check out the related articles below.