Refrigerator Running?

[piscator]

"Then you better go and catch it!" -- remember that one? Awful, unless you're 8 yrs old.

Anyone here have refrigerator experience?

My refrigerator cycles all day long, except for brief periods when it stops and the silence surprises the h-ll out of me! Had a repair guy in who didn't do anything but look at it, suggested the top door hinge might be bent and proclaimed it's not worth fixing. With Porsche parts strewn across my living room, I find that hard to accept.

The frig is a SubZero 736TC that I found on Craigslist. The owners bought a new house that couldn't accommodate the frig, so I got a 'take it now' bargain. It ran fine when I bought it. Outwardly, it seems to be built like a tank and it does stay COLD! (Maybe 'cause it runs all day).

Any thoughts, suggestions, mods? (I could install the York compressor out of my 911). Seriously, if I had to replace all the major components, how hard could it be? Compared to rebuilding a Porsche. The condenser, compressor, etc. should be replaceable, but what I know nothing about is the electronics at the top of the box that control the thing. Are those boards prone to failure?

I've tried google searches, but there don't seem to be any DIY, Pelican-like, forums for SubZero reefers. I contacted the factory and was told that there are no service manuals (at least not for customers). Online, they offer a install PDF and a marketing brochure. The only diagrams I can find are at online parts suppliers.

Lastly, the d-mn machine seems to know that I'm writing this because it hasn't made a peep these last five minutes. We'll see how long that lasts! Update: it lasted another five minutes and is now running.

[jhynesrockmtn]

I have no good advice about your fridge but will say stay away from Samsung if you replace or for anyone out there looking. We just had a 4 year old Samsung hauled out of here, deemed not worth repairing. Ice maker and defrost issues are all well known and there is currently a class action lawsuit in mediation against the company. Out of warranty and company's response is FU. The repair techs have said the manufacturers are trying to stuff so much tech into these things they just are not built to last.

[piscator]

Jerry, that's good to know but it's surprising -- Samsung is so good at so much.

Update: strange discovery, the frig stops running as soon as you pull out either of the two lower freezer drawers. Never noticed that until just now.

[wdfifteen]

Refrigerant could be low.
Defroster could be on the fritz - coils iced up.
BAD door leak - not likely.
Dryer could be clogged.
Condenser coils could be dirty
Condenser fan could be not working.
Compressor leaks (not pumping enough pressure)
A good repairman will check the evaporator coils for ice and warm spots, check the condenser coils for dirt or obstructions, check the condenser fan, and check line pressures. If they don't do that, don't pay them.

[GH85Carrera]

We are lucky enough to have bought our fridge 21 years ago. Everything works. The ice maker does not have a filter at all. One of my friends had a new fridge. It wanted him to install a new filter all the time, and they were over 50 bucks each.

His fridge quit. He started looking around and of course new fridges are insane expensive, and full of gadgets to break. He looked around on Craig's List and found a nice fridge that was 10 years old, but did not cool very well. He bought it for 50 bucks. Then he bought a saddle tap, and some refrigerant. Recharge it, and it works fine. He risked pay 50 for junk. He won big with a nice fridge, no internet crap or bells and whistles no one really wants. Just keep things cold in the fridge, and frozen in the freezer.

Good luck.

[aschen]

Is it young enough to be modern (confuser controlled)? Many fridges have a technicians diagnostic sheet hidden in them somewhere. I discovered this a year or so ago when my brandnew whirlpool started acting up. There is a spec sheet hidden in the hinge with all the diagnostic modes and tests. It lets you do thing like manually cycle the individual motors and checks the thermistors.

[billybek]

Check the easy stuff first.
Door seals are not surprisingly a big deal.
Take a dollar bill, (or a 5 dollar bill in Canada) and close the door on it and try to pull it out. If the door seals are making good contact, there will be some resistance.
Put your hands under the doors and feel for cold air falling out.
Air that falls out needs to be replaced with warm air that has moisture in. Now you are sensibly cooling the new air and drying it out which puts a high latent load on the system. Frost forms on the coil that acts as an insulator and reduces heat transfer. All those things increase run time.
Easy stuff first. Door seals, condenser cleanliness, condenser fan operation, evap fan operation, frost on evap, evap fan.
Is the frost on the coil being melted away in a defrost cycle? No?
Defrost heaters or defrost timer or controller. Possibly defrost termination switch.
Compressor? Cold suction line, warmish liquid line, hot discharge line.
The very last thing I would do is line piercing access ports if the compressor doesn't have them.
They are leak potentials and you lose a decent amount of refrigerant every time you hook up a gauge to them.

[ossiblue]

Call a tech that specializes in SubZero as they will know how to tap into the controls and see what's going on.

We've had SubZeros for over 30 years and they are like tanks. Our previous one had a continuous fan operation, but the compressor cycled only when necessary. It seemed like the fridge was ON all the time, but it was just the fan. Our latest one, same model, does not do that and is much quieter and there is no sound unless the cooling cycle is on. Just be sure that the sound you hear is actually the compressor and not just the circulating fans.

Seems to me if it is actually running all the time, either you'd get too cold in the fridge section or, as mentioned, the refrigerant is low and that's why it continually runs. Leaking seals, misaligned doors will show up as frost/excessive moisture inside the box.

[Por_sha911]

Clean the coils. Look for some underneath that may have years of dust on them.
I had a "dorm fridge" that started running all the time. It was freezing everything. A $15 thermostat fixed it. Put a thermometer inside and see if the temperature is too high or low.

[908/930]

Try to find the temp sensor and make sure it is sitting where it belongs, could be the dead band on the temp controller set too narrow, possibly worn out, not sure if that would be adjustable. Could also be shutting off because of another sensor ( pressure or high temp) before the temp controller reaches proper temp. Is the fan or fans all working?

A proper repair person should be able to tell you what is really going on.

How hot is the compressor getting before it turns off? If it gets quite hot this could be low charge.

[Zeke]

I think fridges run more these days than older models.

"The manufactures stopped using the electric [door] heaters and started running a pass of the hot condenser tubing on the edges of the cabinet where the electric heaters use to be. This is often called a yoder loop tube SxS version and the yoder loop tube Top freezer version. This has now replaced the electric heaters. If you feel heat/hot around the door opening of your refrigerator you should....

clean the condenser coils as a dirty condenser can make the tubing hotter than normal
check/clean & replace if necessary the condenser cooling fan ( # F ) motor, if the condenser fan motor is slow or has quit the yoder loop pass will get very warm/hot to the touch
If the condenser coils are clean and the condenser fan motor is running ok, check the fresh food and freezer section temperatures...if the refrigerator is not operating well and the temps inside are warming up, you could feel more heat/warmth than normal."

In ‘single circuit appliances’ and appliances with a 4-star freezer compartment, temperatures are usually regulated according to refrigeration compartment temperature. When ambient temperatures fall, an issue arises because the refrigeration compartment will not need to be cooled as regularly and this means that the associated 4-star freezer compartment can then become too warm. In such cases, the refrigeration compartment is artificially heated by a light bulb or an electrical heater to force the refrigerator to cool down more frequently and thus keep the 4-star freezer compartment sufficiently cool.

I had to look up what the 'stars' mean for freezers. While the Sub Zero may not be a 4 star freezer, the concept is interesting.

Source: https://blog.liebherr.com/appliances/my/refrigerators-heaters/

However, I did look up your fridge and you have separate cooling systems. Could it be that one runs and then the other runs during the 'off' time to save on amp draw?

[piscator]

WOW! You guys are amazing!! I will start to troubleshoot based on your suggestions.

Service in my area is a problem. I believe SubZero 'protects' service territories and in my area uses a local appliance repair company that doesn't seem to know the brand all that well. The nearest guy after that is twenty miles away and I'm not sure he'd come.

I'll report back when I know something. Thanks so much!

[piscator]

Originally Posted by wdfifteen

Refrigerant could be low.
Defroster could be on the fritz - coils iced up.
BAD door leak - not likely.
Dryer could be clogged.
Condenser coils could be dirty
Condenser fan could be not working.
Compressor leaks (not pumping enough pressure)
A good repairman will check the evaporator coils for ice and warm spots, check the condenser coils for dirt or obstructions, check the condenser fan, and check line pressures. If they don't do that, don't pay them.

Thanks to everyone for the help! My frig is now as 'quiet as a church mouse.' I can't tell you what a relief it is to have the quiet back! WD, special thanks to you for the straightforward checklist!

I emptied the frig and disassembled the interior for cleaning. There was water on the floor of the frig, so I suspected ice on the evaporator; which is behind the interior back panel. By the time I got everything apart there was no ice, just water. On to the condenser.

The condenser and condenser fan are mounted to a panel that rolls out of the front bottom section of the frig. Makes it pretty easy to get access to everything. The panel also houses tw compressors, one for the frig and one for the freezer.

There was some dust on the condenser which I vacuumed away. I do this regularly, but there's a new puppy in the house contributing to lint quotient. The main problem, however, was the condenser fan. The old fan was running, noisily, and apparently not moving sufficient air through the condenser. I replaced the condenser fan and the problem disappeared.

This fridge was a Craigslist bargain that I bought because I loved the engineering. I paid less for it than I would have for a mid-priced unit from an appliance store. I have to say that working on it was actually fun. Not unlike working on my Porsche. Everything is logically thought out and accessible.

The problem is getting parts! My model was not the most popular, so parts are hard to come by, even from the big online sources. Fortunately (in a rare example of foresight) I stock-piled two evaporator fans and a condenser fan when I bought this SubZero.

Thanks again for the great help and motivation!! And, in appreciation, there's some beer and carrot cake in there -- help yourself!