True TDD-1 - Major Ice Inside and Not Cooling

[Massive Subpoenas]

I picked up a used True TDD-1 about a year ago, it worked well for about 6 months but lately I've had these problems:

1. Ice is forming inside the unit, in the area directly above the drain hose nub (where the plastic drain hose attaches). I believe there are cooling coils located above where the ice is forming. Lately I've been leaving the unit open in between kegs, and all the ice melts. When I start it back up, it usually takes about 7-10 days for the new ice to "overflow" the tray below the coils, at which point it starts freezing to the underside of the tray and is visible when looking inside the unit.

2. The interior of the kegerator will not go below about 44 degrees F regardless of where I set the temp dial. The coils (or are they fins?) on the compressor are pretty rusty. I don't know if that's what's causing it.

Any help is greatly appreciated - thanks!

[THE ICEMAN]

Two or three things to check...

Make sure the condenser coils (down by the compressor) are clean on the surface & deep inside the coils.

Check to see if the temperature control turns off the compressor when turned to the warmest position - fully counterclockwise.

The other possibility is that the unit is low on refrigerant.

All these things can make the compressor run continuously causing the ice buildup.


THE ICEMAN

[Massive Subpoenas]

OK - I cleaned the coils last night and will check temp when I get home this evening.

The coils are rusty, so I'm not sure if that's affecting performance.

As for the temp control, when I first ran the unit I had to keep the dial at 1 (lowest setting) since any higher would cause the beer line to freeze. It also seemed that, even on 1, the compressor ran a lot. But with it on 1, it kept the beer around 33-35 deg. F. Maybe I need a new temp control???

(Of course, now it doesn't matter what setting it's on - it won't get colder than mid-40s deg F.)

I guess if none of these work I'll have to look into the coolant.

[BrewGuru]

Sounds like a Bad T-Stat, or low on refrigerant and doesn't reach the cutout, but ICEMAN has much more experience with this, so you might wait for him to chime in again before doing anything else.

SOMEtimes if the t-stat is dying you can adjust the cut in and cut out on a t-stat that's gone wonky and it will help get some more life out of it, other times it's just time for a new one - mechanical ones range from $20-$50 depending on the type, cap tube length, etc... If you are low on refrigerant, that's another ballpark.

[Massive Subpoenas]

Thanks.

Turns out that, after letting the ice melt and cleaning the compressor coils, I'm back to around 32-34 deg F. What an improvement in the taste of the beer (in my case, Yueng Ling).

However, even with the t-stat on the lowest setting (on the 1 setting - not turned all the way off), the compressor seems to run a lot and the temp is near freezing.

So although it's gotten colder (apparently my refrigerant is OK), sound like I need a new t-stat?

[BrewGuru]

Yup, that's probably the case, it sounds as if your cutout temp is not right, it could just be the position of the cap tube (temp sensor) or it could be the t-stat is faulty and needs to be replaced.

At the lowest temp setting the box should be in the 40's and the compressor should not cycle back on for quite some time after cutout...

Tell us, does the compressor ever shut off with the t-stat at the lowest setting?

[THE ICEMAN]

Originally Posted by Massive Subpeonas

Turns out that, after letting the ice melt and cleaning the compressor coils, I'm back to around 32-34 deg F. What an improvement in the taste of the beer (in my case, Yueng Ling).

However, even with the t-stat on the lowest setting (on the 1 setting - not turned all the way off), the compressor seems to run a lot and the temp is near freezing.

So although it's gotten colder (apparently my refrigerant is OK), sound like I need a new t-stat?

BrewGuru has a good line on things. If the temperature control is never shutting the compressor down that could be the reason for your miniature icebergs. Once again, does the compressor ever shut off?

But wait...

An additional question - Was the evaporator frozen evenly from top to bottom or was it just frozen solid at one end or on the bottom half of the evaporator?


THE ICEMAN

[Massive Subpoenas]

When the t-stat is set at 1, the compressor does shut off, but not very often, and not for a very long time (at least to me - it seems like the thing runs about 90% of the time). And, the compressor does not shut off immediately when it's set to 1 - it always keeps running then shuts off later. The only way I can get the compressor to shut off is to keep turning the t-stat knob past 1 - then the compressor shuts off but the fan continues to run.

I actually don't know if the unit shuts off less frequently at settings of >1 because I never set it above 1. (Is there any way I can tell if I need a new t-stat or just need to make an adjustment to this one?)

As for the ice, it seems to first form on the top side of what I'll call the evaporator drip pan (the sheet of metal into which the plastic evaporator drain hose connects upwards into). From what I can tell, it freezes uniformly across the entire bottom of the pan, until the ice goes over the lip of the pan, at which point water begins dripping over the back of the pan, and the ice then begins to form on the bottom of the pan (the is the ice you can see when opening the door and looking into the back of the unit). The visible ice forms on the very back of the pan, and starts out on both sides of the middle, then slowly expands outward to each side.

The ice does not favor one side over the other.

Also, I noticed last time that vertical blocks of ice are also present in a small (3" wide maybe) vertical cavity on each side of the cooling coils - the ice blocks are between the coils and the side of the unit (I felt the blocks with my fingers).

Let me know if my (admittedly lame) descriptions of the interior are too confusing and I'll take a photo and post it. Thanks again for your help.

[Massive Subpoenas]

I should also add that this unit is kept outside (in the shade) on my patio here in Miami. I've had some exterior condensation issues, but other than that, the hot outdoor temps don't seem to be a problem. (We had a very nice winter this year, but even on the chillier nights the unit ran near-continuously.)

[BrewGuru]

From your description, the unit is not low on refrigerant, if it's icing over evenly, and hitting the pan! the evap is getting plenty cold, if it was only on one side, that would be different.

It seems you've felt the ice on either side of the evap coil, have you removed the evap cover and looked at it directly?

At the beginning of your post I was initially thinking "it HAS to be a bad t-stat", but then I read Miami and outdoors! So, the next question, are all your door seals in good condition, no tears or holes, etc? Do the doors align properly, any other leaks or holes in the unit? And how often do you open the doors? If you've been using it like a refrigerator and grabbing bottles, cans, or other items frequently, this could be part of your problem. There are ways to rig a unit if you need this capability, like a mini vinyl strip curtain, etc...

With the high ambient temps in your location, and the unit being outdoors, it's already working higher duty to remove the heat from inside the box, add to that the relatively high humidity level and door cycling - boom! you've got a prime conditions for the evap to freeze over!

[Massive Subpoenas]

OK - I should have included that detail earlier - sorry.

The thing is that it seemed to run just as frequently over the winter when days were in the mid-70s and nights in the 50s.

As for leaks, the doors/seals appear to align, I'm not aware of any holes. I only open the door to change kegs (in which case the unit gets shut off and cleaned) and, lately, for 2-5 seconds to check the temp inside.

The exterior condensation is generally on the tower, as the insulating foam is very thin (I should probably get something thicker, and I will try that).

I am interested in doing whatever I can to bulk up the insulation - any suggestions are greatly appreciated.

[doug ellis]

Just for your info. I have True TDD1, and I live in Boynton Beach. The unit is inside, so your conditions and mine will not be the same. I have my T-Stat set on 2. With keg in unit (two weeks now) the compressor will cool down to 32o. Then will warm up to 40o before it kicks on again. Run time to cool back down to 32o is 15 min. You mentioned the fact your fan runs even after the compressor kicks off. That is normal ( commercial units all do this)it is the circulating fan. It helps to keep the tower cool. Keep in mind my unit is about 12 years old and it may not be working at it's best. Just the same it serves me well and would not think of replacing.

Good luck with your icing problem

[Massive Subpoenas]

Unfortunately I'm back up to low- to mid-40s all the time, regardless of t-stat setting. I've turned it off and left the door open slightly to melt the ice (again), after which I guess I'll get a few days of cold beer, then repeat.

Can anyone advise on how to remove the evap cover so that I can take a look at what's going on inside?

After all this, I think I have an evap drainage problem. I never seem to get any water in the evap pan on the outside bottom of the unit - I also don't seem to get ice in the evap pan hose, so it's like none of the evap drips ever drip out of the unit - they just freeze up instead. Any thoughts???

[BrewGuru]

Sorry to hear your temps are up!

Evap covers are pretty easy to remove on these units, there are visible screws securing a bent flange that you remove, and the evap cover, with fans mounted to it, rocks or drops down, the you should be able to see the evap coil and observe what's going on while the compressor cycles.

When you leave it open to defrost, are you turning the t-stat all the way down? The ideal way to defrost is with the evap fan(s) running, but the compressor not cycling, the airflow will really help with the speed of the defrost!

[jfs999]

I had the same problem with a Bev Air DD68. I had the condensor, condensor coils and thermostat replaced back in February and it worked great for a couple of months. All of sudden the evaporator coils started icing up and I could'nt get the temps below the mid fortes. I called the repair guy back and he checked everything out - all was okay. He couldn't figure out why it wasn't cooling down and it kept icing up - he even swapped out the t-stat for another new one. He finally (after 3 trips) decided to replace the freon (RG-22 or whatever - can't remember the exact number). He drained the system and recharged it again and it started working fine - no icing. Don't ask me why it worked - it doesn't seem to make sense to me, but he had done it before on rare ocaasions. Might be worth a try - sounds like you tried everything else.

[Massive Subpoenas]

BrewGuru - When defrosting I pull the plug. Next time I will try fan only - should I leave the door open to expedite the process or leave it shut (ambient temps here in the summer are a miserable 80-90+ deg F and high humidity)?

Doug - When you have the temp fluctuations, does the beer temp fluctuate as well or stay relatively constant?

jfs999 - I need to find a good repair guy (Doug - any suggestions?). Any idea on what to expect to pay for a visit and refrigerant charge?

Thank you.

[doug ellis]

Originally Posted by Massive Subpoenas

BrewGuru - When defrosting I pull the plug. Next time I will try fan only - should I leave the door open to expedite the process or leave it shut (ambient temps here in the summer are a miserable 80-90+ deg F and high humidity)?

Doug - When you have the temp fluctuations, does the beer temp fluctuate as well or stay relatively constant?

jfs999 - I need to find a good repair guy (Doug - any suggestions?). Any idea on what to expect to pay for a visit and refrigerant charge?

Thank you.

Now that you bring it up, I have never checked the beer temp. during cycle. If I had to guess, I would think constant. Have to get a new keg tomorrow, will check that and get back to you.

[BrewGuru]

Massive,

It's up to you whether or not to leave the door open during defrost, it will go faster with it open and the fans running, but you will maintain a cooler internal temp with them closed, your call.

It really sounds like you have a T-stat issue, the t-stat's cap tube should go along the back wall and catch air from the evap, if it's been pulled or bent forward it might not be shutting off, which could be causing your icing problem...

Check the routing of the cap tube on the t-stat and let us know if it looks like it got repositioned.

Alternatively if your unit has been retrofit with an aftermarket t-stat, sometimes people use lower temp cutout ones where the cap tube goes right into the evap coil, you will need to ensure it is making good contact with the evap tubes - they are usually placed with the cap tube / sensor near the end of the run, and if you are low on refrigerant this area of the coil might not be getting down to temp.

[THE ICEMAN]

Originally Posted by BrewGuru

Massive,

It really sounds like you have a T-stat issue, the t-stat's cap tube should go along the back wall and catch air from the evap, if it's been pulled or bent forward it might not be shutting off, which could be causing your icing problem...

Check the routing of the cap tube on the t-stat and let us know if it looks like it got repositioned.

Alternatively if your unit has been retrofit with an aftermarket t-stat, sometimes people use lower temp cutout ones where the cap tube goes right into the evap coil, you will need to ensure it is making good contact with the evap tubes - they are usually placed with the cap tube / sensor near the end of the run, and if you are low on refrigerant this area of the coil might not be getting down to temp.

I hate to tell you there BG but all True units use the cap tube into the evaporator method of sensing temperature. The only exceptions would be on some freezer models where it senses air temp.


THE ICEMAN

[BrewGuru]

Oh jeez! Thanks!

Even though it's in the title of the thread, I somehow forgot that we were talking about a True unit!

Carrier/Bev-Air uses t-stats that measure the back wall air Temp.
True uses t-stats that are in direct contact with the evap.

Sometimes one or the other unit is rigged with the wrong kind of t-stat, that's what I was getting at.

[drab08]

hey everyone, i know this thread is a couple of months old now but i am having this exact same problem. Every symptom is the same and the only difference as far as i can tell is the fact that i live a couple hours further north and my True is kept indoors. Has there been any resolutions to this? I would love to know why i continue to get ice in there. I don't remember if this was mentioned by the original poster or not, but once i defrost my unit entirely it will easily get down to my desired sub-40's temp...that is, until it freezes again. Then it maintains that 43-44 degree temp. Any further assistance would be greatly appreciated.

[drab08]

does anyone have any further ideas?