Replace Your Evaporator Plate | Isotherm Elegance 130

Introduction/ Disclaimer

I’m going to be frank: this is a long post. However, if you seriously want to replace your evaporator plate in your Isotherm Elegance 130 refrigerator, I suggest sitting back, relaxing, and getting into this document. I wish so deeply that Zak and I had something similar to this while we were going through this problem. With this in mind, I have compiled everything I think you need (and maybe more) to help you get through this project as a complete newbie (like we were). Remember, Zak and I are NOT professionals by any means, just people who are trying to become more handy everyday and keep more stuff out of landfills. While this may not be the ideal refrigerator repair the way a repair guy may do it, it’s what we had and it has worked for us, so it *should* work on your 12V fridge as well. Lastly, we got all of our information from Clark and Emily’s Adventures. Make sure to check out their 3 part series on AC and Refrigeration before attempting this fix!

Getting Materials

The next day I drove down to Bozeman to get all of the materials at ACE, Harbor Freight, Home Depot, and AutoZone. You can read about my trip here. While the blog post linked is a little more detailed, here are the materials that I ended up with:

Materials:

• New evaporator plate
• Triangular metal file
• Darning needle/ Pin
• Copper tube cutter
• ~3ft of 3/16” copper tubing
• Steel wool
• Flux
• Flux Brush
• Solder (Lead Free)
• Butane or propane torch
• Butane or propane
• Some sort of insulation for your tubes
• Some sort of putty/ caulk/ sock to fill the hole between the actual fridge and the area where the compressor is
• 2– ¼” flare nuts —> if you want to use flares to bring suction tubes together
• 1/4″ Flare Union —> if you want to use flares to bring suction tubes together
• Copper Flare Tool —> if you want to use flares to bring suction tubes together
• Refrigeration-safe Thread sealant —> if you want to use flares to bring suction tubes together
• Valve/Gauge set (with 3 tubes and 2 gauges)
• Vacuum pump
• 1 small can of 134a Refrigerant
• 134a can tap
• 1/8″ brass pipe fitting (or similar) –> used if you want to solder suction tubes together

Getting Down to Business (To Defeat the Huns)

The day after getting materials, Zak and I got down to business to start fixing the fridge. I think the worst part of fixing anything new or really doing anything new is that it’s scary. But all we can do is jump in, right? Go slow, you’ll gain more confidence as you go. Before we get started, it’s a good idea to familiarize yourself with some vocabulary. Here are some words that you should know and some notes you should heed:

Cap tube= capillary tube= very, very small diameter copper tube that high pressure liquid refrigerant flows through. A capillary tube is a type of tube and can be used for different purposes. In this case, there is a capillary tube on the inside of the fridge that works as a thermometer (this is silver in color on our fridge), and there is also a copper-colored coiled capillary tube mostly on the outside of the fridge. This is the capillary tube that we will be referring to and working with (unless otherwise stated).

Suction Tube= Bigger tube (1/4″ diameter) that the capillary tube is attached to. The suction tube connects the evaporator plate to the compressor. (In a sense, the capillary tube does this as well, but it isn’t nearly as obvious.)

Low Pressure Access= LPA= Where you will hook up the blue tube of your gauge set. Attached to the compressor. (Some compressors have both high pressure and low pressure access points, this particular fridge only has a LPA). While High Pressure Access points are useful for diagnostics, they are not necessary. The only absolutely necessary access point for adding gas and vacuuming is the LPA.

Flux= a cleaning/ primer type agent for soldering. The solder will tend to go where your flux is. Don’t use too much.

Evaporator Plate/ Coil= The part of the fridge that keeps it cold. Refrigerant moves through the coils in the plate, and heat from the refrigerator is removed via this system, making your fridge cold. If you’ve punctured a coil in the plate, you will likely see a big burst of pressurized gas. This would be an obvious leak. If you have a slow leak, you may not see it/ notice it. It is not always in the evaporator plate. However, if you have a leak, you will notice that the frostline is moving backwards/ your fridge may not be cooling.

Frostline= literally the line at which the frost in your freezer stops. If it seems to be receding (only a certain part of your fridge is cold) you may have a slow leak.

Notes

1. If working on a fridge from a company (ours is an Isotherm Elegance 130), you will very unlikely be able to unsolder the joints made by the manufacturer without oxygen/a brazing torch. Therefore, you will leave those pre-soldered joints alone and cut/join at other areas of the tubes.

• Particularly for the Isotherm Elegance 130, there is ANOTHER capillary tube that comes from the ceiling inside of the fridge (it is silver) and attaches to the evaporator plate, THIS IS NOT THE CAP TUBE WE ARE GOING TO CUT. This is likely the thermostat, and should be gently disassembled from the old plate, and reassembled in the new plate.

Part 1: Replacing the Evaporator PLate

Taking Apart the Fridge

1. Remove the evaporator plate. The one for this fridge is held in by 2 screws in the front. Don’t break the plastic faceplate. This you will have to disassemble and put on the new evaporator plate. (See video for how to disassemble).
2. You’ll notice that the suction tube goes out of the fridge through a hole which is filled with putty. GENTLY remove this putty with a butter knife or equivalent. (Don’t puncture anything! This is how you got into this mess in the first place!) 
3. Particularly for the Isotherm Elegance 130, there is ANOTHER capillary tube that comes from the ceiling and attaches to the evaporator plate, THIS IS NOT THE CAP TUBE WE ARE GOING TO CUT. This is likely the thermostat, and should be gently disassembled from the old plate, and reassembled in the new plate.
4. As the old evaporator plate is still attached to the compressor, you will need to cut the suction tube line in order to completely remove the old plate. I suggest cutting the suction tube in a place that is FAR from where you will be working. This gives you a practice space to learn how to use the tube cutter as well.

The Suction Tube

There are 2 ways that we show you how to bring together the old suction tube and the new suction tube. Firstly, you can use a flare fitting. For our particular fridge, this required 2 — 1/4″ flare nuts and a 1/4″ flare union, as well as a flare tool and some thread sealant. Unfortunately, we did not leave enough space on our new suction tube for both the flare nut and the flare tool, and our flares were, well, dinky. If you are familiar with flare fittings though, this is not a bad way to do it, and you can totally go this route! However, if this does not work for you, you can go the way we ended up going, where we found a 1/8″ brass tube fitting which we used as a joint to solder the old suction tube to the new suction tube. If you are looking for your own fitting, we highly suggest bringing a small piece of your copper tubing to an ACE or equivalent store and see which brass fittings make a nice fit around your tube.

Joining the Suction Tube with Flare Fittings

1. The suction tube is attached to the coiled capillary tube and is much larger in diameter (¼”). It is mostly painted white and it is not coiled like the capillary tube is. For us, we are going to cut (with a copper cutter) the old suction tube off where our white paint ends which is just before the capillary tube shoots off of it, and about 5 inches from the entry to the compressor. (I realize that your fridge may not look like this, and you may need to find your own place to cut.)
2. Once you get the new evaporator plate with its new suction tube in place, you will want to cut the suction tube about 3″ from the white paint, closer to the end of the tube with the rubber stopper (you can see this in our video). Again, you MUST have space for both the flare nut AND the flare tool on your copper tube to make a good flare. Also, you want to leave yourself space in case you mess up and need to cut off your crappy flare and make a new one.
3. For the ends of the suction tube that you are going to join together, you will be using a flare fitting. The tools for this can be found at harbor freight or online.
4. Next, PUT THE FLARE NUTS on the two ends you will be joining FIRST! Once the metal is flared, you’re not getting the flare nut on, and you’ll have to start over! When you put the flare tool on the copper tube, make sure that the copper stands about 1/8″ proud of the flare tool. This will ensure your flare is large enough. Once the flare is created, you will join the two ends with a ¼” flare coupler, which can be found at ACE Hardware (or online). If you would like, you can use a thread sealant, but make sure it is ok to use in refrigeration settings, and don’t use too much, because you don’t want it to get in the line!
5. And that’s it! (The suction tube wasn’t so hard, was it?!)

Joining the Suction Tube by Soldering

1. The suction tube is attached to the coiled capillary tube and is much larger in diameter (¼”). It is mostly painted white and it is not coiled like the capillary tube is. For us, we are going to cut (with a copper cutter) the old suction tube off where our white paint ends which is just before the capillary tube shoots off of it, and about 5 inches from the entry to the compressor. (I realize that your fridge may not look like this, and you may need to find your own place to cut.)
2. Once you get the new evaporator plate with its new suction tube in place, you will want to cut the suction tube about 3″ from the white paint, closer to the end of the tube with the rubber stopper (you can see this in our video).
3. Clean the ends of the new and old suction tubes with steel wool around where you will solder. Solder will not stick to unclean copper. You may also want to try to steel wool the inside of the brass fitting you bought. There isn’t really any reason why it should be dirty in there, but better safe than sorry right?
4. Next, using your flux brush and flux, paint a small amount of flux (a thin layer) right where you will be soldering the brass fitting to the suction tubes. You don’t need a lot.
5. Next, you will gently heat the brass fitting with your torch, (DO NOT HEAT THE SOLDER) and gently touch the solder to the hot tube. Via capillary action, the solder should move right around the area that you need to join. Make sure that you get solder all the way around the outside, remember, we don’t want leaks. Also, I am totally not a soldering expert, so you may want to watch a few YouTube videos on this.
6. Anyhow, solder both the new suction tube and the old suction tube to the brass fitting, and you should be good to go!

** Also, I shouldn’t have to say this, but obviously when soldering you are using fire and creating very hot metal. Use gloves, have a fire extinguisher, protect yourself and your property! Safety, safety, safety!

Part 2: The Capillary Tube

1. Cut the capillary tube (teeny coiled copper tube) using a triangular metal file. File around in a circle until most of the way through, and then snap off the soldered end of the capillary tube. DO NOT USE A COPPER CUTTER ON THIS! Once your capillary tube is cut, take a darning needle and stick it into the tube to make sure that the hole is nice and hole-y.

Note: The only reason why this is soldered shut is because this is a pristine, brand new evaporator plate and no crap is getting in there before you’re ready to work!

2. You need to make sure that your new cap tube and your old cap tube are approximately the same length. Different lengths (significantly longer or shorter) will change the way your fridge works. (You won’t be able to be super accurate, especially with the coil, but you can estimate.) Zak and I did this by counting the coils on each tube, finding/marking the halfway point, and cutting there.
3. Next, take about a foot on the end of each capillary tube (the old and the new) and VERY GENTLY straighten it out. Straightening out the cap tube is actually deceptively difficult. Go slow, and wear gloves if you need (it’s a bit tough on the thumbs.) DO NOT KINK! Kinking will mess up how your fridge runs because it changes the already tiny inside diameter of the cap tube! You will want to use about 3 feet of 3/16” copper tubing, and this will act as your “joint” when you join the old and new cap tubes.
4. Make sure your capillary tube is SQUEAKY CLEAN by using steel wool to clean it. You want a nice shiny copper color. Fine grit sandpaper would also work, but the sand grit can get into the capillary tube and mess things up, so steel wool is better. Shine, shine, shine!
5. Stick that straightened out foot of capillary tube into the 3/16” copper tubing you just bought. It will be a floppy-ish junction. You do not want to have the capillary tube stick into the 3/16” tube like a cork in a bottle (i.e., very tight) because then the solder has no place to go.
6. Next, add a little flux to the capillary tube where it joins with the 3/16” tube, but not too much. Flux is a cleaner/ primer for soldering. The solder will go where the flux is, so it’s important to put the flux just around where you want the solder to go (which is NOWHERE NEAR THE OPENING OF THE CAP TUBE!!—We do not want solder to block the capillary tube. This is why we are using such a long joint to join the capillary tubes.) To make sure you don’t use too much solder, you can make a little hook or bend in the rod, this helps you keep track of how much you have used. Remember, too much solder can move right up into the cap tube and block it. Yikes!
7. Next, you will gently heat the capillary tube with your torch, (DO NOT HEAT THE SOLDER) and gently touch the solder to the hot tube. Via capillary action, (name unrelated to the capillary tube), the solder should move right around the area that you need to join. Because you will be joining the 3/16” copper tube and the capillary tube about a foot away from the open end of the capillary tube, there shouldn’t be much concern that the solder will be close to or block the capillary tube opening.
8. Remember, your capillary tube (now with the addition of this 3/16” copper tubing) STILL needs to be approximately the same length as your old capillary tube, so when cutting the other side of your cap tube, make sure everything will still be the same length-ish once it is all soldered together. You may need to slightly mold/ snake your new joint so that it fits within your allotted refrigerator space, this is ok. As a note, this area with the 3/16” tube around it may get cold once the fridge is running because of the pressure and phase changes occurring in the refrigerant between the cap tube and the 3/16” tube. This is also ok and normal. Just make sure that you put some thermal insulation around this area.
9. To solder the other side of the capillary tube into the 3/16” copper tube, GENTLY straighten out a foot of capillary tube from the new/old cap tube (depending on which side you started with) and repeat steps 4-7.
10. That’s it! You now have your new capillary tube soldered in!

Part 3: Evacuating and Recharging The Fridge

Evacuating the Fridge

1. For this project you will need to buy or rent a valve/ gauge set and a vacuum pump. I bought mine at Harbor Freight. I bought the 2.5CFM vacuum because it was cheaper, but there is also a 3CFM version. Make sure that the valve/ gauge set has 2 valves (high and low pressure) and three tubes coming out of it. In Harbor Freight, I found these all in the “automotive” section of the store. The tubes should be red (high pressure), blue (low pressure), and yellow (for vacuum and gas addition). Less tubes on your valve set will not work. You will also need a small can of 134a refrigerant (can be bought at AutoZone) and 134a can tap. Both the refrigerant and can tap are sold at AutoZone.
2. When putting together the gauge set, make sure that all of the valves are closed and that the depressor side of the tubes are going to be hooked up to your fridge/ vacuum.
3. The low pressure access (LPA) port on the Isotherm Elegance 130 is right below the spot that we cut on the suction line that went from white to copper. The LPA is bent at an approximate 90 deg. angle and has a Schrader (tire) valve at the end. You will hook the blue line to the LPA. At the end of your gauge tube, there is a small depressor. This depressor is meant to push down the Schrader valve in the LPA. Make sure to adjust the depressor so that it is long enough. We didn’t do this at first, and it caused a whole bunch of issues. There are wrenches for this type of thing, but I just used a pair of tweezers and turned it a little bit.
4. For this particular refrigerator, there is no high-pressure access point. So close the valve to the red line, and ignore it completely.
5. For the Vacuum, you have to make sure that there is oil in it for it to run. The Harbor Freight version comes with oil. It has an 8.5 oz. capacity. Watch the video/ read the directions to fill up appropriately.
6. Once oil is appropriately full, hook the yellow line to the vacuum. (as far as I can tell, it doesn’t matter which port you use on the vacuum, but I used the top one). Make sure the blue valve is closed. Turn on the vacuum.
7. Next, open the Low pressure valve while the vacuum is running and let it run for about 15 mins until the pressure gets to approximately -30 to -32 PSI. Then shut off the valve. The system should hold the vacuum, which means that the PSI number should not move. If the pressure starts to become less negative, this means you have a leak in your system, and you need to go back to make sure these are taken care of before you continue. If the system holds the vacuum, continue on to the next step. If the pressure doesn’t go down at all, make sure you don’t have a huge, gaping leak!
8. If there is no leak, go ahead and open the low pressure valve again and let the vacuum run for about 3 hours. You want to get every single bit of moisture out of this system before you refill. Moisture in the system will wreak havoc on your fridge. Let the vacuum pump run.

Recharging the Fridge with 134a

1. –3 hours later— okay! Now you can shut off both the vacuum and CLOSE THE LOW PRESSURE VALVE. (if you keep it open, you will see that pressure will return to 0, meaning you have just ruined the vacuum in your fridge!) You can take the yellow tube off of the vacuum.
2. You will now need to move your fridge to a place where you can hook it up to DC power. If that means back in your van or boat, move it there. The compressor needs power in order to suck in gas. Hook your yellow tube up to your gas canister.
3. Turn the compressor on. If you have an AC fridge, this means it needs to be plugged in to a 120VAC outlet, and if you have a 12V (DC) fridge, then you need to hook it up to your 12VDC batteries.
4. Now open up the gas (R134a) valve. Up at the gauges, slowly loosen the yellow tube just until the tube leaks. Just let this happen for about 2 seconds. This ensures that only refrigerant is in the yellow line now, and that we won’t be shooting any atmosphere into the fridge. (All that air we spent so much time sucking out with the vacuum!) **NOTE** DO NOT tip the gas can on its side, as this can cause liquid refrigerant to go into the system, which we do not want. Always make sure that the can is going up and down. Also, try to keep your can warm if possible. This will make things go more quickly.
5. You will want to add refrigerant until your low pressure gauge reads about 7 PSI. Once this happens, let the fridge run and cool down. As you add gas, you will see that the gauge will start at a higher pressure and then move down, this is normal as the gas moves through the system. Once the fridge has been running for a while and the pressure does not move below 7 PSI, the system is happy!

As a note, if you notice that the suction tube OUTSIDE of your fridge unit is starting to become frosty more than a foot from where it exits the refrigerator, you have put in TOO MUCH GAS! If the frost line backs up all the way to the compressor, this will be very hard on the compressor. Let out some gas little by little and let the system equilibrate. Frost a few inches outside of the fridge is fine, but more than that is too much gas.

The YouTube Video