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JCD2292KTYB Jenn Air side by side not enough cooling

moisheh

Premium Member
Joined
Sep 23, 2017
Messages
9
Location
Canada
Model Number
JCD2292KTYB
Brand
Jenn-Air
Age
6-10 years
Our Motorhome has a built in Jenn Air JCD2292KTYB. It is a 2008 model. It has always worked well. 2 years ago After sitting unused for 6 months I started the fridge and it would not cool. Compressor was running. I called a repair tech. he and his son are a good team. The father has 35 years experience. After checking a few basics he installed 2 piercing taps and hooked up his gauges. There was Freon in the system. he evacuated and installed the gas you use for leak checking. Held pressure for 3 hours!

Father says that the newer fridges operate with a negative pressure and sometimes the system gets plugged. I am not a tech and really did not understand. he over pressurized the system and it immediately began to cool. We had the fridge on for 600 days and it was perfect. The unit sat unplugged for 5 months. Same problem appeared. Father repeated the fix and all was good. Fridge ran for 4.5 months but now the problem has reappeared.

The freezer was at 28 degrees and the fridge at around 48. I unplugged it last night and just now started it up again. I have it set at -4 and 36. That is where it normally is setup. Any suggestions on how to fix it permanently appreciated. If it was in a house I would just buy a new fridge. But changing a fridge in a motorhome is a big deal. The drivers side window has to come out and the seat removed. The new fridge has to be close in dimensions. Not easy to find. Thanks
 

rickgburton

Appliance Tech - Moderator
Staff member
Joined
Jul 11, 2006
Messages
36,343
Location
Murray, Utah 84107, United States
You're refrigerator obviously has a refrigerant leak. It just a matter of finding the leak and repairing it. If the leak is in the evaporator you may need to replace the evaporator. Depending on the type of service valve, if not removed they will develop a leak eventually.

The refrigerator doesn't operate with "negative pressure". R134a refrigerant has a lower boiling point than the older R12 so the machine operates at .5 to 5 lbs of pressure on the low side. When the machine loses refrigerant the low side pressure will drop into a vacuum (neg pres). If the system becomes restricted or partially restricted the same thing will happen because of the cap tube size. It's not important to know how the system works but in case you're interested I'll post it:

REFRIGERATOR SEALED SYSTEM: HOW IT WORKS
All conventional refrigerators manufactured today, from the less expensive mini-refrigerator to the high end models, all
use one basic refrigeration system that consists of a compressor, condenser, capillary tube and evaporator. The
compressor is a pump, because the pump in a refrigeration system is always used to compress the refrigerant, it’s
referred to as a compressor. When the refrigerator is turned on, it starts the compressor. Since the intake of the
compressor is connected to the evaporator, it begins to pump out some of the refrigerant gas from the evaporator. As the
refrigerant gas is removed the pressure in the evaporator begins to drop. If there is any refrigerant liquid in the evaporator
it will immediately start to boil because of the lowered pressure, absorbing heat of vaporization in the process causing the
evaporator to get cold. The cold evaporator will, in turn, absorb heat from warmer food in the refrigerator. The refrigerant
pumped out of the evaporator is forced into the condenser tubing where it is compressed into a high pressure gas
because of the restriction presented by the capillary tube prevents it from flowing through as rapidly as the pump can
pump it out of the evaporator. As the compressor runs more and more, refrigerant is pumped into the condenser so that it
becomes highly compressed and its pressure builds up. Compressing a gas concentrates its heat and raises its
temperature. The hot refrigerant gas, at this point, contains the heat it started out with plus the heat it absorbed from the
food compartment. The highly compressed gas can be quite hot. As the hot gas flows through the condenser coils it
begins to cool, giving up some of its heat to the surrounding air. At this point the refrigerant contains less heat than when
it entered the compressor even though its actual temperature is very much higher. At this lower temperature some of the
gas condenses to a liquid and gives off the heat of vaporization which it absorbed when it boiled in the evaporator. By the
time the refrigerant has traveled through the condenser all of it has become liquid and given off all the heat of vaporization
it absorbed from the food compartment. After condensation, the liquid refrigerant continues to flow, first through the
filter/drier where any contaminants like moisture are removed, through the capillary tubing into the evaporator where it
boils again. This cycle continues as long as the compressor is running. In order for the refrigeration system to work
properly, some restriction to the flow of refrigerant is placed at the entrance to the evaporator. This prevents the
refrigerant from flowing too fast into the evaporator so it maintains a low pressure in the evaporator as the compressor
pumps it out at the other end. At the same time the restriction causes the refrigerant to pile up in the condenser and
capillary tube raising its temperature and pressure and permitting it to give off its heat of vaporization. The refrigerant from
the outlet of the capillary to the inlet valve of the compressor is at low pressure. This is referred to as the low side. The
refrigerant from the output of the compressor through the condenser and capillary tubing is at high pressure and called the
high side. The capillary tubing offers the restriction necessary to separate the high side from the low side outside the
compressor.
 

moisheh

Premium Member
Joined
Sep 23, 2017
Messages
9
Location
Canada
The tech evacuated the system and filled it with a gas( I forget maybe nitrogen) It held pressure for a few hours. No leaks. He says the system is partially restricted. He overcharged it slightly and in no time at all it was cooling. He says there are no leaks?? It has been running 24 hours and it finally reached 31/41. Are you saying it is not restricted? The service valves he installed are piercing valves. I am sorry I do not know more than that. I could take a photo of the valve Thanks
 
Last edited:

rickgburton

Appliance Tech - Moderator
Staff member
Joined
Jul 11, 2006
Messages
36,343
Location
Murray, Utah 84107, United States
Let me explain it this way; Problem, the machine stops cooling. Tech comes and adds gas, the machine cools. Then same problem. The tech comes and adds gas, the machine cools. Then same problem..... If the system was a restriction all this gas he keeps adding would still be in the system and the system would be overcharged. The refrigerator won't cool if overcharged. If he read his gauges correctly the first time he should know if the low side is in a vacuum and there's high head pressure, it's restricted. If the head pressure is normal or below, there's a leak.

It held pressure for a few hours doesn't surprise me. You went almost two years between the first and second refrigerant charges so this is a small leak. The reason it shows up after sitting for a while is due to the low side pressure. Most leaks are usually found on the low side. When the machine is in use, most of the time it's operating at a half pound of pressure up to maybe four pounds of pressure. When it's not in use the two pressures equalize so you have higher pressure in the low side.

This type service valve is called a bullet valve or clamp on style service valve. They will leak eventually and should be removed after each use.
R-service valve 2.jpg
This style is called a braze on service valve. They don't leak if installed properly.
R-service valve 1.jpg
 

moisheh

Premium Member
Joined
Sep 23, 2017
Messages
9
Location
Canada
I want to thank Rick and Jake for their help. We are still in Mexico and I have been unable to get a tech to drive he 60 miles to our house. Finally I found a fellow. I asked if he had equipment to leak detect with Nitrogen. He said of course I have a truck full of tools and parts. He came out today with 2 of his workers. They come from the big city and love to come out here and have fresh seafood. They all had on clean clothes and uniform shirts with his logo.

You have to understand that sometimes when a plumber comes he has a small tool bag and NOTHING! he saw those temporary fittings on the lines and immediately said : I think that is your problem. Your fridge is in a Motorhome and everything vibrates. He also said those are not meant to be permanent ( same comments as Rick!) he hooked up the gauges to the temporary fittings and said there is almost no gas. he soldered 2 fittings and charged the system.

In no time at all the temp started to drop. he was watching the gauges all the time. Stayed until the fridge dropped to 38 and the freezer was 20. within a short time after he left the fridge reached the set temp of 37 and -3. He told me that these fridge compressor rarely go 15 years. He also said that when he opened the lines there was a little oil. That was the blockage. Told me to let him know if the compressor seems to be labouring. Maybe in a few years.

He understood that because it was in a motorhome changing to a new fridge would be a big deal. he would come out and install a new compressor. But first they clean the whole system with some type of liquid. I know this is not something that techs do in the USA. But in Mexico things don't just get tossed. To top it off the labor and gas was less than what a tech would charge just to drive 10 miles to your house in the USA. he was super guy and I am happy. Thanks again to the forum!
 

rickgburton

Appliance Tech - Moderator
Staff member
Joined
Jul 11, 2006
Messages
36,343
Location
Murray, Utah 84107, United States
I know this is not something that techs do in the USA.
We do, it's called a flash charge. We charge the system with a small amount of refrigerant, run it through the system, then vacuum it out before recharging the system. R134a is not a forgiving refrigerant. It doesn't mix with anything. Glad to hear your refrigerator is working. He sounds like he knows what he's doing.
 
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