Kegerator Issue - Compressor Constantly Running

[Brushwood Brewing]

I have a Beverage Air DD50 kegerator that I got for a steal (~$150) on Craigslist last year from a bar in Philly that had closed down. It had been running great for the past year, but as of last week the compressor has started running constantly. It still maintains the 38F-40F temperature fine, the compressor just won't cycle off.

From some quick google searching, it sounds like it may be low on freon. Does anyone have any tips on troubleshooting and diagnosing the issue to confirm for sure?

I feel like I have enough DIY confidence to replace a faulty thermostat, but not to recharge the freon. My wife has always been supportive of the hobby, but I'm not sure how much of our family funds we could put toward a service technician coming out...

My beer thanks you.

 

[day_trippr]

Compressor constantly running could indicate the unit is low on refrigerant. It'd take a little $$ to find out, but the same $$ could then assist in recharging the unit. If you can access the suction line to the compressor, it's not hard to do. Check out my thread here

Cheers!

 

[Brushwood Brewing]

@day_trippr Thanks for the quick response. That looks like a detailed post, I'll have to find some time to read through it thoroughly and decide if that's something I'm comfortable doing.

In the meantime, I've put the kegerator on a timer, 30 minutes on and 60 minutes off, to give the compressor a break. It's hovering around 45F at that rate.

 

[Broken Crow]

I just took a quick peek at the manual for your kegerator and was reminded of the first used commercial unit I bought.... I had to spend a fair amount of elbow grease and water cleaning out the coils...not too sure what kind of environment it had been in, but they were pretty much plugged with filth...especially condenser coil in the back; damp dust practically turns into cement.
After cleaning, it cycled far less and didn't even begin to build up ice on the evaporator.
That said; It may be more likely the refrigerant and like @day_trippr says it's not that hard to do, especially with that excellent post he made about it.

 

[whoaru99]

I think this is a case where one has to weigh the risk an even higher repair bill or potentially whole unit replacement vs. cost to recharge it.

The refrigerant not only facilitates the beverage cooling but also distributes the internal lubricant and such for compressor longevity.

 

[day_trippr]

There is only on item in a fridge that needs lubrication and that's the compressor. All oiled compressors have an oil sump (which is why one is advised to let the unit sit upright for 24 hours if moved on its side or back) and that oil won't stray far enough to matter...

Cheers!

 

[whoaru99]

There is only on item in a fridge that needs lubrication and that's the compressor. All oiled compressors have an oil sump (which is why one is advised to let the unit sit upright for 24 hours if moved on its side or back) and that oil won't stray far enough to matter...

Cheers!

Are you suggesting, aside from poor cooling, the unit will suffer no ill effect from continued operation with the low charge?

 

[Broken Crow]

Are you suggesting, aside from poor cooling, the unit will suffer no ill effect from continued operation with the low charge?

The oil, while it mixes freely with the coolant is simply heavier and drops to the compressor. Unless you're doing an entire purge and recharge, as long as the unit has remained upright, gravity keeps the required oil where it belongs and adding refrgerant happens over top of that.

 

[day_trippr]

^exactly^

 

[Brushwood Brewing]

@day_trippr I think you've convinced me to try it. The kit you recommended from Amazon is no longer available. Looking through other kits, all the adapter pieces look slightly different from one another, but I'm assuming they accomplish the same thing. I'm planning on going with this kit.

You mentioned not wanting to vacuum purge due to the high cost. I've heard elsewhere that some people have been able to borrow A/C vacuum pumps from Autozone for free. If my local Autozone offered that, would you recommend going that route? What are the benefits and/or additional risks?

 

[day_trippr]

That kit is a superset of what is needed (the three cylinder valves is why) but the price is so cheap it's still a decent buy. For a purge and fill, otoh, it takes a full manifold/gauge set, a vacuum pump, and if you're going to be legit about it, a capture container.

While I did not know all that could be borrowed (which is awesome) I do not believe such a slow/small leak would justify/require a purge and refill. My unit never lost more than a third of the full gas volume. If it had bled out entirely, that'd be different, as the potential for air ingress (and the accompanying moisture, which is the killer) would exist in that case...

Cheers!

 

[dtashmore547]

there is often one other item to check, that is the door seal. of not sealing properly it will allow the cold air to escape.

 

[JohnDBrewer]

I have developed the same issue of the kegerator running constantly. It's a commercial version and in the back it has this capped tube leading directly to the compressor. Could I tap into that to add freon or is/was that used for something else.

 

[day_trippr]

Unless that capped end leads to a tee, it'd be an oil fill port.
If it does lead to a tee you need to determine if it's on the suction side or not, as that's the side to add refrigerant.
The output tubing from the compressor will be hotter than the suction side tubing.

 

[Bobby_M]

I was going to suggest either the thermostat or the relay is stuck on (welded contacts) but then it's pretty likely the temperature would go below refrigerator temps for a while. It's still possible but you would find the evaporator coil completely iced up (is it?). There's a point where so much ice builds up on the coil that it because extremely inefficient can can't pull heat out of the box.

 

[Brushwood Brewing]

@Bobby_M Thanks, but no unfortunately the evaporator coil isn't iced over. I checked that already. And I actually cleaned the coils just a couple months ago, so @Broken Crow I don't think it's dust either.

It's sounding more and more like a freon issue. I've ordered the recharge kit, and will pick up the 134A from my local auto parts store this week. I'm planning to give it a go on Saturday. I'll update once I do. Thanks again for the help everybody.

 

[hotbeer]

For automobile and home air conditioning units, a frozen over evaporator coil is the first sign of having too little freon. The evaporation of the freon going through it gets too efficient when the freon levels drop.

Too much freon results in not enough evaporation to cool things. But obviously it worked at one time in the past. Maybe now something happened to the orifice and plugged it up or a flaw made it's opening get too wide for efficiently evaporating the freon.

But I suppose it might have gotten to the point that there isn't enough to evaporate at the coil. And that suggests a leak that will just have you wasting dollars trying to keep it topped off with freon.

So not seeing that frost or ice might be a indication it's something else entirely. Are you even certain the compressor is actually on? Maybe you are hearing something else.

 

[Brushwood Brewing]

Are you even certain the compressor is actually on? Maybe you are hearing something else.

Yes I'm quite certain the compressor is on. My home office is the same space as my brewery, so I work 2' away from the kegerator every day. I'm quite familiar with the sound both with the compressor on and off. Also, the compressor felt warm when i checked it this week.

 

[Brushwood Brewing]

Okay I just learned there's a difference between the condenser coil and the evaporator coil. (Like I said... not confident on refrigeration DIY.) So yes, @Broken Crow I did clean the condenser coil, but no @Bobby_M I did not check the evaporator coil.

Side note now relevant to ice buildup on the evaporator coil: A month or two ago I noticed there was some dripping inside my kegerator, which resulted from my drain line freezing up, near what I know now is the evaporator coil. At that time it did look like there was some ice buildup on my evaporator coil. That was shortly after I tried turning the kegerator to a cooler setting. So after I noticed the leak, I ended up turning the kegerator back to a warmer setting (~40F) and that took care of the leak.

That being said, my compressor was not running constantly last month when I saw the buildup and leak. And, my wife took our toddler & baby out of the house today, in part to give me time to work on this. So I'm still going to try to recharge the system today while I can, but if that doesn't fix it I'll look into replacing the thermostat and/or relay.

 

[PCABrewing]

Unless that capped end leads to a tee, it'd be an oil fill port.
If it does lead to a tee you need to determine if it's on the suction side or not, as that's the side to add refrigerant.
The output tubing from the compressor will be hotter than the suction side tubing.

A lot of refrigeration units (dorm fridges, boats, campers, portable dehumidifiers) have only one port on the high-side of the system that is used primarily for the original factory fill (oil and refrigerant) and yes it will be hotter than the low-side (suction). You can still charge through that high-side port but you MUST never do so with the unit running for risk of the can bursting or liquid refrigerant entering the compressor and locking it up. The compressor can easily develop enough pressure to burst a refrigerant can. R22 is a bigger risk than R134, but even a 134 system can develop high (120+) PSI. R22 can be sitting at 170 PSI with the compressor off and inside a hot cabinet can be 250+PSI.

Frequently there is a tag on the system somewhere that states the refrigerant type and usually the weight of a full fill that is important if you are going the evacuate and recharge the system after a repair.
I have encountered older mini-fridge systems that use R22 but they are rare.

Many small systems aren't really designed for service as the low cost of the unit makes them "disposable" since a service call might cost as much as a new unit. Some have no fitting at all, just a stub that is crimped and soldered after the factory fill.
Most systems can be repaired if you have the knowledge and skill-set but may cost more than it's worth to do so.

Unplug before connecting the gauge set or charging hose, and always wear goggles or safety glasses, frostbite on your eyeball is contraindicated.

As previously stated if it is low on refrigerant, there is a leak somewhere and a recharge doesn't fix that, it just prolongs the inevitable. And it is a guessing game to add the right amount to restore to factory spec.

 

[day_trippr]

Nobody is claiming a fix here. I kept my dying keezer alive for almost six months while accumulating the parts for and then assembling its replacement. As for recharging, adding a BPV to the suction side is nbd, and bringing the loop pressure up to an acceptable level is easy. Total fill is typically noted on the manufacturer's build plate...

Cheers!

 

[Bobby_M]

I have a 3-door unit that has a broken auto close spring on one of the doors. When one of the other doors slam shut, occasionally the broken one will pop open. One time the unit ran all night due to the door being cracked open and all the incoming moist air froze the coil solid. It was doing the same thing here. Held set temp for a full day but never shut off because there was no airflow over the coil.