Ice on cap tube & liquid line, refrigerator not cold

It needs refrigerant gas, it has a slow leak somewhere. Call for service.

Are your asking about TXV valve thermal expansion valve for A/C system ? If you are ,yours doesn't have one . Has an orifice tube , The orifice tube is located in the liquid line between the condenser and the evaporator !
The orifice tube is the dividing point for the high and the low pressure sides of the A/C system. As the refrigerant passes through the orifice tube, the pressure on the refrigerant is lowered. Due to the pressure differential on the liquid refrigerant, the refrigerant will begin to vaporize at the orifice tube. The orifice tube also meters the amount of liquid refrigerant that can flow into the evaporator.
Unless you are referring to the auxiliary A/C system for the back of the vehicle , it uses a
The rear TXV is located at the rear evaporator inlet. The TXV is the dividing point for the high and the low pressure sides of the rear A/C system. As the refrigerant passes through the TXV, the pressure on the refrigerant is lowered. Due to the pressure differential on the liquid refrigerant, the refrigerant will begin to boil at the expansion device. The TXV also meters the amount of liquid refrigerant that can flow into the evaporator.

Very unusual for a household fridge, but ice build up on the lp side(suction) normally indicates to much charge (gas) in system or if compressor starts to become less efficient, valves dont seat 100% which causes a liquid build up on the line. If the evaporator fan motor stops, this can also create that problem.(assuming the fridge wasnt cooling properly). Many occasions when a new compressor is installed, the technician might put a little to much charge in by mistake. Normally a machine puts in an exact amount that has been dialed in.

If the evaporator tube is iced up entering the coil and cool to warm leaving the evaporator, that would indicate low on refrigerant or a restriction. If it is iced up entering and leaving the evaporator, then, it could be low on refrigerant,blower not running at proper speed, dirty evaporator coil or filter.
You need to check the suction and head pressure and temperature to determine problem for sure.

Good day,
Unusual question.
Lots of reasons. You didn't say if it was cooling or cycling off and on.
1. Evaporator fan motor in freezer compartment not running. Doesn't allow the refrigerant to boil off and returns as a liquid.
2. Evaporator coil badly frosted allowing no air flow thru it. Same as #1
3. Runs constantly (days). no demand on system, and once again will not boil off before leaving evaporator.
4. Overcharged. Floods back excess charge.
5. Heat exchanger came apart. The capillary tube is soldered to the suction line to transfer heat from the cap tube to the suction line. Necessary on a refrigerator. Common problem.

Hope this helps
Thanks for using fixYa

That is called a " cap tube separation " . It can be caused by overlooking a defrost problem for too long . If the coils inside of the freezer frost up , that frost , will eventually work its way out thru the back toward the compressor . When it does this , the " low side ( suction ) " , receives liquid refrigerant , instead of gas . This liquid refrigerant , will destroy the compressor internal valves , causing it to loose the low side . ( Never charge a refrigerator low side with liquid , only gas . The high side can be charged with liquid . ) A cap tube separation , is when the pressurized ( causes heat ) cap tube , becomes separated from the low side ( suction ) tube , causing the suction tube to frost up , due to the cap tube no longer attached to it . When this happens for too long , the only repair , is to replace the compressor AND repair the separation , with wire ties , thermal putty sealant and aluminum tape .
I apologize for the technical explanation , but there is no other way to explain it .

Some units the orifice is in the evapoator, where the liquid line connects to the distributor and some are in the liquid line at the evaporator. The best way to find it, is to run the unit and follow liquid line at the evapoator, the line will be warm on one side entering the orifice and cold and sweating on the other side leaving the orifice.

Your evaporator coils frost up in normal use and every eight hours or so the entire unit shuts down and the defrost heater comes on to melt the frost. This cycle last about 20 minutes. The melted frost drips into a drain pan and through a drain tube to the drain tray under the freezer/refrigerator where it's evaporated by the condenser fan.


If the evaporator coils behind the back panel of the freezer are icing up because of auto defrost failure that will stop the circulation of cold air
check defrost timer, defrost heater, defrost thermostat. In most newer models they don't have the timer but an electronic device which replaces the timer.

if you have a gas leak then you find the liquid boil off very early in the evaporator only, there should be no visible frosting until after the end of the capillary

MOST CASES ... THEY ARE NOT LOW ON 134A . TO TELL ... YOU NEED ONLY START THE COMPRESSOR AND HOLD YOUR HAND ON THE SMALLEST COPPER-LINE ... IF IT GETS REAL HOT 110-130 DEGRESS YOU HAVE A CHARGE. IF YOU MOVED THIS FRIG. AT ALL LATELY MAKE SURE YOU LET IT STAND UPRIGHT UNPLUGGED !!! FOR EIGHT HOURS. YOU CAN ALSO SPEED THINGS UP BY: HEATING WITH A BLOWDRIER BOTH THE COLD PLATE INSIDE AND THE BOTTOM OF THE COMPRESSOR ... THIS BOILS ANY REFRIGERANT OUT OF THE OIL AND LETS THE OIL RETURN TO THE COMPRESSORS OIL RESEVOIR THAT IS AT THE BOTTOM OF THE COMPRESSOR. THESE SMALL FRIGS ARE GREAT ... BUT FRAGILE TO MOVE AND DEFROST. OIL CAN GET TRAPED IN THE COLD PLATE AND NEDDS TO BE HEATED OUT OF THERE AND SOME UNFORTUNATELY USE METAL OBJECTS TO DE-ICE. A LOW CHARGE WILL NOT FROST THE COLD PLATE (EVAPORATOR)EVENLY AS IT SHOULD. LOW CHARGES (AFTER YOU HAVE DONE THE ABOVE) ... WILL ICE UP IN JUST A SMALL SECTION WERE THE PIPES AND CAP-TUBE GO INTO THE COLD PLATE. THESE DONT LEAK UNLESS SOMEONE TOOK A ICE-PICK OR EQUALLY AS DEVESTATING TOOL TO DEFROPST IT. ONLY WAY TO DEFROST QUICK IS WITH HAIR DRIER ...DO NOT PROP-IT UP IN THERE AND WALK AWAY .. YOU CAN MELT OR WARP INSIDE PLASTIC HOUSING !!!!! THEY ALL NEED MANUAL DEFROSTING THE MINUTE ICE STARTS ACCUMILATING. OR BUY A APPLIANCE GRADE HIGH AMP (10 AMP) PLUG IN TIMMER AND SET TO GO OFF AT 3AM AND COME ON AT 4PM ... ONLY 1 HR. IF THERE IS A VISABLE HOLE IN THE EVAPORATOR COLD PLATE ... IT IS ALUMINUM AND FORGET ABOUT EXOPY KITS TO REPAIR THEY ONLY LAST A YEAR IF THAT. IF YOU CALL TO HAVE IT REPAIRED RIGHT WITH SOLDER ... USUALLY A REPAIR LIKE THAT WILL NOT BE WARRANTIED AND PROBUBLY COST MORE THAN TO BUY A NEW ONE. GOOD LUCK.