39 replies to this topic

[Big Nake]

When I starting using my larger fridge as my draft fridge (4 kegs inside and an analog Johnson controller), I noticed that my drafts were warmer than I would like. I'll admit... I like cold beer. So I started turning the controller down. The beer was colder but still not as cold. At some point, I set the controller to 28° and a thermo inside the fridge read around 35°. I just left it and figured it was okay. Today I'm having a few while watching the Cubs & Blackhawks and the thermo in the fridge now reads 40°. I just moved the temp controller down to 25° while saying This is nuts! to myself. Somewhere in there I moved the probe inside the fridge in case it was getting a weird reading or something. Has this happened to anyone else or does anyone know what's up? How could my temp controller and a thermo be 15-20° off? Cheers.

[ThroatwobblerMangrove]

When I starting using my larger fridge as my draft fridge (4 kegs inside and an analog Johnson controller), I noticed that my drafts were warmer than I would like. I'll admit... I like cold beer. So I started turning the controller down. The beer was colder but still not as cold. At some point, I set the controller to 28° and a thermo inside the fridge read around 35°. I just left it and figured it was okay. Today I'm having a few while watching the Cubs & Blackhawks and the thermo in the fridge now reads 40°. I just moved the temp controller down to 25° while saying This is nuts! to myself. Somewhere in there I moved the probe inside the fridge in case it was getting a weird reading or something. Has this happened to anyone else or does anyone know what's up? How could my temp controller and a thermo be 15-20° off? Cheers.

That seems crazy. Why not just rely on the fridge to maintain the temperature? Since it's just cold storage this shouldn't be a big deal (no active fermentation, etc.).

[BrewerGeorge]

zym may have something. Is it a fridge or a freezer with an analog controller? If it's a fridge, it might not be able to get as low as you're asking it to get.

[Big Nake]

Hmm. Well, this is a fridge (and my serving fridge) so although it's not for fermentation, it IS for keeping my kegs at the temp I like to serve them at. Does a typical refrigerator temp controller go down into the low 30s? I know that the newer ones do, but this is an old-school GE fridge that is probably 25-30 years old if not older. Maybe I should have just tried to set the fridge controller w/o using the Johnson, huh? OTOH, I just wonder if the issue here is "probe placement" (that's what she said). I have moved it around a little bit and it seems to fluctuate.George, when you say "if it's a fridge, it may not get as low as you want it to get...", doesn't the Johnson controller override that? The controller just makes the fridge kick in more often which keeps the temp where the Johnson is set, right?

[BrewerGeorge]

Hmm. Well, this is a fridge (and my serving fridge) so although it's not for fermentation, it IS for keeping my kegs at the temp I like to serve them at. Does a typical refrigerator temp controller go down into the low 30s? I know that the newer ones do, but this is an old-school GE fridge that is probably 25-30 years old if not older. Maybe I should have just tried to set the fridge controller w/o using the Johnson, huh? OTOH, I just wonder if the issue here is "probe placement" (that's what she said). I have moved it around a little bit and it seems to fluctuate.George, when you say "if it's a fridge, it may not get as low as you want it to get...", doesn't the Johnson controller override that? The controller just makes the fridge kick in more often which keeps the temp where the Johnson is set, right?

The Johnson will only turn power to the fridge on and off. The fridge will have its own temp controller that probably won't go below 38F or so. Just because the Johnson controller sees a temp that's too high and turns ON, the fridge won't turn itself on until it gets to its own low setpoint. Try setting the fridges controller to its lowest setting and see what that gets you.

[Big Nake]

The Johnson will only turn power to the fridge on and off. The fridge will have its own temp controller that probably won't go below 38F or so. Just because the Johnson controller sees a temp that's too high and turns ON, the fridge won't turn itself on until it gets to its own low setpoint. Try setting the fridges controller to its lowest setting and see what that gets you.

The fridge's internal controller is set to "coldest". This is pretty weird because I have 3 other fridges in the house where the fridge's internal controller (if set low enough) will freeze beer. Is it possible that this old fridge won't go that low?

[BrewerGeorge]

... Is it possible that this old fridge won't go that low?

Certainly. Especially if the coils are dirty.

[ThroatwobblerMangrove]

The fridge's internal controller is set to "coldest". This is pretty weird because I have 3 other fridges in the house where the fridge's internal controller (if set low enough) will freeze beer. Is it possible that this old fridge won't go that low?

I think I'd just let the fridge run with it's own thermostat set to coldest and see where that gets you. I like to use a glass of water or something similar b/c it has some smoothing built into it already so it will give a pretty accurate temperature.

[Big Nake]

I'm bumping this thread because I have been playing with this a little bit. The temp controller on the fridge (by itself, turned to "coldest"), does not go any lower than it does with the temp controller, so that doesn't seem to be the solution. Depending on where I put the probe for the controller, I seem to get a few degrees difference, but the beer is still not quite as cold as I would like it. This is an old-school GE fridge. I'm not sure of its age, but the cooling lines are at the very top of the fridge (if you open the door and look up, you see them) and the fridge is all metal inside... not plastic like newer models. I know that the other big fridge I have in my bar will freeze things if I turn it down low... but does anyone see any way to get this thing to go lower? I thought the temp controller would override the fridge's controller. George, what do you mean by dirty coils? I don't really know anything about fridges... is this something I can fix myself? The thought of getting a different fridge for this purpose has crossed my mind (ugh!).

[gnef]

If it can't go any lower without the controller, then you are out of luck, unless you replace the controller inside the fridge. The external controller can not get the fridge to go lower than the fridge would otherwise.

[Jimmy James]

The only thing I can think Ken is that the probe on your external thermostat is registering a lower temp than is actually ambient in the fridge and cutting power to the compressor. I had this same problem once where I couldn't get the fridge and controller temps to match - very frustrating. You may need to keep experimenting with placement of the probe. I always found that sticking the probe onto the side of whatever I was trying to cool and putting a thin layer of foam over then duct-taping it down worked good. Otherwise what would happen is the fridge would kick on, cool the air inside quickly and then the controller would shut it off. It would take ages for 5 or 10 gallons of wort/beer to equilibrate and if there was active fermentation going forget about it. If you tried running the fridge for a few days without the external controller hooked up, and it didn't get below 40dF then it likely either needs cleaning on the coils like George said, or perhaps even some of the coolant leaked in which case you're SOL. Did you try removing the external thermostat completely and let it sit for a couple days, maybe with a thermometer in a glass of water?

[BrewerGeorge]

If it can't go any lower without the controller, then you are out of luck, unless you replace the controller inside the fridge. The external controller can not get the fridge to go lower than the fridge would otherwise.

This. A temp controller can only make a fridge or freezer warmer than it would naturally get on its own. It can't make it colder.

[ThroatwobblerMangrove]

I thought the temp controller would override the fridge's controller.

As others have said Ken, this won't get you any colder. Imagine you are doing the job of the temp controller. All you can do is plug the fridge in and unplug it from the wall. The best (coldest) you are ever going to do is what the fridge can do on it's own. Could be time for a new fridge

[Big Nake]

Ugh. They must have made fridges "warmer" in the old days because my new ones (one big and one small) will freeze a bottle of beer if you set it too low. I guess I thought that the temp controller just kept the fridge running longer to get the desired temp (because the fridge is plugged into the controller, the controller tells the fridge when to turn on and off). I guess I will continue to play with the probe and see what that does. If that doesn't work, I may consider looking into a cheapie new fridge at the Sam's Club or whatever. [homer] Stupid Homebrewing! [/homer]

[ThroatwobblerMangrove]

I bought a fridge at sears a year or so ago and it easily fits 5 soda kegs. I think it was about $400.

[3rd party JKor]

You may be able to bypass the internal thermostat on the refrigerator, then use the Johnson as the primary controller. The problem could simply be that the internal thermostat is cheap and inaccurate. That's why there is no temperature number on the thermostat dial (just cold...colder...coldest). When you are GE and you're buying fridge thermostats by the millions and you only want to pay $0.82 per unit, you don't care much if the actual range is 35 to 45 or 38 to 48.Before we go any further, let me ask this...is this a standard upright fridge/freezer combo?

[Big Nake]

You may be able to bypass the internal thermostat on the refrigerator, then use the Johnson as the primary controller. The problem could simply be that the internal thermostat is cheap and inaccurate. That's why there is no temperature number on the thermostat dial (just cold...colder...coldest). When you are GE and you're buying fridge thermostats by the millions and you only want to pay $0.82 per unit, you don't care much if the actual range is 35 to 45 or 38 to 48.Before we go any further, let me ask this...is this a standard upright fridge/freezer combo?

Yes, standard upright freezer/fridge combo. Old. White. The handle is chrome with some simulated wood-grain paper on it. I'd say 70s-ish. The cooling elements/capillaries (whatever you want to call them) are exposed and are suspended from the ceiling of the fridge. When I have the fridge turned down as far as it can go like this, some ice builds up on those cooling elements. Also, I realize this is weird... why do I have a temp controller on this "serving" fridge (FRIDGE, not freezer)? That's because once upon a time I used this fridge for lager primaries and wanted to control the temp. But when I turned it into my serving fridge, I just kept using the controller. Also, I did disconnect the external temp controller (an analog Johnson) a few weeks ago just to see what the internal controller would do. It seemed like the temp went up to about 40° when I did that. So I reconnected the Johnson. With the Johnson connected, it seems to go a little lower... say 38°. But last night I moved the probe and it's now resting on the top rubber part of one of my kegs and the thermometer that's in there now reads a little lower than 34° so maybe I just need to get things just so and I can skate with this thing. I was drinking yesterday and grabbed a glass from the freezer so that first beer was COLD. But each beer after that just seemed slightly warm which prompted me to resurrect this thread. Thanks guys.

[harryfrog]

Did you clean the external coils like someone suggested? They should be located either behind the fridge or under the fridge. A good dose of compressed air (the dusty method) or a gentle brush with a paintbrush coupled with a shop-vac should take care of the dust / cobwebs. These are what express the heat to the environment and should help the fridge run efficiently.As to the ice forming on the coils, this may be shutting down the fridge prematurely if the coils freeze. A small fan in the fridge circulating the cold air should help this. Have it switch on with the temp controller and see if that helps.

[3rd party JKor]

The location of the probe for the internal thermostat will have an effect as well. If it's close to the coils, it will shut off sooner. I think the best way to start out is to get a fan to recirculate the air in there. Evening out the temperature may solve the problem.If you can locate the probe for the internal thermostat, you could put some insulation over it to get the temp to drop a little more. It's probably in a hidden location, though.

[Big Nake]

Thanks guys. Harryfrog, I think that part of the internals are exposed in the back of the fridge. I see a large round tank sort of thing (the compressor?) and I will look for coils. I generally don't like to poke around in areas that I don't know anything about, but I will see if I can locate the coils and see if I can clean them up.