TROUBLE SHOOTING FREEZER PROBLEMS
All Commercial Freezers have similar and basic components that are common. For example, all freezers will have a compressor, condenser, and evaporator.
AND all commercial freezers will also have similar and basic reoccurring problems. Most of these problems are user or consumer related. I will address some of these issues here:
A. LACK OF MAINTENANCE: I have already address this in other places on this site so will not need to redo so here. I do mention it though as it is the most common and reoccurring problem. For more information, see:
B. ICED COIL: When the evaporator coil ices, the ONLY means to correct the situation is to shut the unit down and totally and completely defrost the unit. Often times, consumers try to cheat this process by only shutting the unit down for an hour or two thinking the unit is completely defrosted. Unfortunately, an hour or two rarely is long enough to defrost the coil completely.
WARNING I do not recommend a consumer defrosting a unit without proper training or the assistance of a refrigeration technician. There are several causes for an ice coiled which I will discuss in great detail at:
C. POWER ISSUES: there are certain wiring issues that can develop a problem after a period of time and will not show themselves immediately. One of these problems is wiring 208/230 volt powered unit with 3-wires (combining the neutral and the ground wires together). I have addressed this issue at:
D. BAD START COMPONENTS: This one is tricky as most refrigeration techs confuse this one with a bad compressor. It is imperative to know hoe to test if a compressor is good or bad. There are different ways to diagnose this and to test - some use an electrical test to see the amp draw. This is a good way to check the compressor. However, a better way is to use an "Annie" or hermetic compressor analyzer. Unfortunately most techs do not carry one of these nor have they ever heard of them. That said, when a compressor is weak or gets too hot, often times in takes out the start capacitor or the relay. There are numerous ways to verify or check these and they must be done before automatically declaring the compressor is bad. For more details on starting components, see: STARTING COMPONENTS for further info and details.
SPECFIC "COMMON" PROBLEMS WITH
TRUE * MASTER BILT * BEVERAGE AIR
As goofy as this may sound, I always recommend starting with the most basic search while trouble shooting freezer / cooler problems....thus; Let's start by checking for adequate "Power to the unit". Now I know that sounds mundane, BUT hear me....this is one of the most common and over looked problems today. We need to check the on/off switch, the reset button (if equipped, and the breaker panel).
Most self-contained freezers require 208/230 (with a dedicated 20 amp circuit) power and are particular to just that. Many of customers have told me that 212 volt or 246 volts is "close enough" when in fact it has permanently damaged the starting components, relay, or even the windings in the compressor. A simple volt tester can verify the correct power.
Also - check the cord for cracks, fraying, damage. I can recall several service calls where the only problem was where the cord got damaged when the unit was moved (most likely got caught under the unit).
ALSO: One super common often overlooked problem resides in lack of communication! ~ Here again, some commercial freezers WILL NOT have the interior (evaporator) fans or lights come on until the box has reached a pre-set (from the factory) temperature. I can not tell you how many times a customer has called worried silly that the lights haven't come on only to call back in 15 minutes or so stating they "are now on" as if they are intermittent.
Another common and typical problem is often found in the wiring...
If after a lengthy period of time the lights do not come on and they certainly should have...we typically find the ground wire or the neutral have a bad connection. With 220/208 power, we are feeding the compressor and condenser fans with 220 volt. The lights and evaporator fans will run on 110 power which is made up of one of the legs of the 220. A bad connection will cut out the 110 power. This often times, is easy to discover as the compressor runs but labors and sounds sick. Simply turn off all power (breakers) and check the wiring.
Predictably, each manufacturer has some common problems and areas of trouble...
COMMON / TYPICAL PROBLEMS WITH TRUE FREEZERS
We have discovered one of the most common problems with the True freezer is the factory installed thermostat. Hence, the upgrade the manufacturer has since made to replace the factory original. There are easy and practical ways to test the thermostat. See
Trouble Shooting Thermostat for details and information on how to verify if this is the problem.
For several different reasons, the start capacitor, run capacitor, and/or relay may fail. Often times this is misdiagnosed as a compressor failure.
In particular, when the starter capacitor fails, the unit often will make a humming noise or a clicking noise. In fact, often times this can be a very inexpensive and easy fix. See: Diagnosing Starting Components for further info and details....
The True has male / female plugs near the compressor for the door lights. If one of these plugs comes undone ~ none of the lights will work. This is often overlooked but is extremely common as there is very little room for the plugs and in fact, simply pulling the condensing unit out will often times require disengaging this plug. If it is overlooked when pushing the condensing unit in, the lights WILL NOT work.
~ The True, for example, also is prone to burned out electrical sockets for the lights. This is NOT due to design flaws....it is ALWAYS due to improper bulb installation. The fact is; the replacement bulbs are incredibly expensive....and there are bulbs from the discount home improvement stores that "will fit" the sockets. The problem is, the discounted bulbs are a 12w bulb and are too powerful for the sockets which are wired for a 10w bulb.
~ As is the case with most things in life, you can pay much less for the "cheaper" bulbs up front AND pay a whole lot more once the sockets fry and need to be replaced.
ALWAYS USE THE CORRECT FACTORY RECOMMENDED BULB!
* Ballast: Sometimes the ballast will need to be replaced. Providing everything else has been thoroughly checked over / diagnosed, then check the ballast. This is fairly simple to replace and often times can be purchased from the discount box stores. I strongly suggest one make certain to get the same "size" ballast as the old one. Here again, wrong or incorrectly sized replacement parts can and will cause other costly damage down the road.
COMMON / TYPICAL PROBLEMS WITH MASTER BILT FREEZERS
From experience, the Master Bilt freezer has very little "common" known, obvious problem areas - hence the reason it ranks so high on my favorites list. However, we occasionally get units in that "don't work" or are not properly working. Usually we find a small leak due to vibration in the suction or liquid lines.
However, nine out of ten simply needed to be re-programmed. Interestingly, I often wonder or ask myself how it got "out of programming" to begin with as this is a pre-set function from the factory. Fortunately, re-programing the Master Bilt Freezer is a fairly simple process...if you have the codes. And I do have them... if you need to re-program your Master Bilt Freezer and do not have the codes, please feel free to use the ones I have posted here. Check out: Master Bilt Programming Codes
* As stated above: The Master Bilt seems to occasionally develop leaks. This is not necessarily a factor or design problem but one more of set up, positioning, and/or delivery.
I personally like the "plumbing" of the Master Bilt but it is subject to the tech working on the unit. Extreme caution should be used while pulling the condensing unit out and pushing it back in. A simple "little" vibration unseen can become an expensive repair / service call.
UPDATE ~ June 2010:
The newer MASTER BILT freezers are out....these units have the hermetic compressors (tin cans) which is a great improvement over the semi-hermetic compressors. These units run much more efficiently and are less likely to have compressor failures.
The newer units have been revealing different problems then units of the past. One common problem has been a bad defrost heater for the condensate drain. Though I am not an engineer, personally I think a better design would not involve a hot electrical wire shoved down a plastic drain tube. In my world, water and electricity don't favor well together. The problem here, the heater melts the drain line. This ultimately burns a hole in the drain line which creates a leak. Often times, it shorts out the heater too causing an ice build up on the coil.
TXV Valve (expansion valve): This one stumps me. I have had several units recently that have had bad TXV valves. Honestly, I believe the issue here comes from a previous tech who believes this is a common and necessary adjustment piece. The TXV should rarely, if ever, need to be adjusted or replaced. Coincidentally, it is my belief, this valve is extremely sensitive for adjustment and results. Unfortunately, most techs tweak this looking for immediate results. Once they don't get immediate results, they keep tweaking, thus trashing the valve all together.
FYI: this valve is complicated and expensive to replace. I recently was on a service call where "CLIFFORD" changed the expansion valve for the the customer and charged him $1200.00. That is ridiculous.....And by the way, I was there as the TXV valve was out of adjustment and ironically, had a leak. Clifford didn't even install it correctly!!!
COMMON / TYPICAL PROBLEMS WITH BEVERAGE AIR FREEZERS
The biggest draw back of the Beverage Air freezer is it's 1hp compressor. Now don't be quick to blame the manufacturer for compressor failures because it doesn't meet up to the competition. As a tech, I am more apt to place blame at the end user for premature failure of the compressor. Improper maintenance (cleaning the condensing unit) can be attributed to premature compressor failure. I will mention this as a common problem though as I have seen countless valve plate failures with the Beverage Air freezers. The valve plate can be easily replaced / repaired providing the failure is caught expeditiously. Please note, even with a valve plate failure, the compressor will continue to run and often times will continue to maintain temperature....however; it will do so under a tremendous load on the compressor and if not caught soon, will ultimately damage other critical components in the compressor such as pistons, crank, bearings, etc. These more terminal problems can be expensive and will generally require a new compressor.
~ As it applies to the compressor: I have also come to see lots of Beverage Air freezers with an easy to fix / hard to find leak. Every compressor has a site glass which is used to determine the level of oil in the compressor. For some odd reason, many Beverage Air freezers leak from the site glass.
NOTE: As is with the Master Bilt; I am going to speculate the leak at the site glass is the result of massive or in- excessive vibration. Often times when I am refurbishing a compressor with a site glass leak, I will not only change the oil, but replace the site glass to a "newer" generation site glass. The newer generation glass has an "O" ring and a gasket which is a much better design then it's predecessor.
~ The Beverage Air also has one other common and typical problem that most techs over look and never have been taught to seek out.
* FREEZERS either have a TXV (expansion valve) or a Capillary Tube.
The TXV valve has adjustments on it to open or close the valve to allow or limit the gas flowing through the valve and into the expansion coil. On the back side of this valve is a screen inside the flare nut. This screen is basically an oil filter. I have found countless machines that had absolutely nothing wrong with them other than this screen being plugged.
The screen gets plugged with dirty oil or other contaminants thus restricting the flow of gas. Often times, when a tech puts his gauges on a this unit, he reads low pressures and automatically assumes it is low on refrigerant. He then shots some refrigerant in and notices no change on his gauges. For some reason, he then automatically assumes he needs to adjust the TXV valve.
Oddly enough, the tech is on track with the problem but actually goes for the wrong solution. The TXV valve is factory set and technically speaking, should never need adjustment. Simply changing out the screen can be a quick fix but I don't recommend it.
I like to lock off the service valves at the compressor, remove the lines on both sides of the TXV valve, pressurize the system with nitrogen, and crack the valves open so I am shooting a blast of nitro up the lines thus clearing them of any restriction and oil residue.
NOTE: I do put a rag over each line up top so as not to trash the inside of the box. I also blow one side at a time and often times crank about 150-200lbs of pressure in the system before open the valve and blast the nitro through.