4 replies to this topic

[sphincorp]

DN 248 older model, the evaporator is icing up, tried 2 other used t-stats that i know work, tried another evapoator, the whole coil gets covered in snow whith in 3-4 hours, driving me crazy, any help would be appreciated

[snack dude]

DN 248 older model, the evaporator is icing up, tried 2 other used t-stats that i know work, tried another evapoator, the whole coil gets covered in snow whith in 3-4 hours, driving me crazy, any help would be appreciated

Okay first things first. Is the fan sitting behind the evaporator running? This fan should run all the time blowing cold air up into the machine, and if it is not, it is not pulling air thru the evaporator and it will ice up.

2nd how do you know the thermostats are good? can you cycle the compressor on and off with it. With the compresssor running take the probe and stick it into a glass of ice water. it should not take long for the compressor to kick off. Then reverse the process.

3rd you have an air leak somewhere. warm air is getting into the machine and the moisture is iceing the evaporator.
Check the door seal. Put some vaseline lightly on the seal all the way around the door. Close the door tight like you normally would. Open the door and check the inside frame. anywhere there is no vaseline means the seal is not making contact and sealing.
Check the product door to make sure it is closing all the way and lined up.
Check the drain tube. it should have a loop or crimp in it and preferably a little water to keep warm air from coming up the tube.
Check the spot with the tubes and electrical cables come thru from the compressor. make sure there is a nice tight fit and it is sealed with plumbers putty or electrical putty.

After all that Im stumped

Good Luck

[snacksnorma]

DN 248 older model, the evaporator is icing up, tried 2 other used t-stats that i know work, tried another evapoator, the whole coil gets covered in snow whith in 3-4 hours, driving me crazy, any help would be appreciated

[snacksnorma]

The info about the fan is the first thing to check. Also make sure the area is cear of debris (lint, leaves etc.) anything that can block the flow of air.
It is also possible that there may be a refrigerant leak. A unit low on refrigerant will ice up.

[wooowooo]

Okay first things first. Is the fan sitting behind the evaporator running? This fan should run all the time blowing cold air up into the machine, and if it is not, it is not pulling air thru the evaporator and it will ice up.

2nd how do you know the thermostats are good? can you cycle the compressor on and off with it. With the compresssor running take the probe and stick it into a glass of ice water. it should not take long for the compressor to kick off. Then reverse the process.

3rd you have an air leak somewhere. warm air is getting into the machine and the moisture is iceing the evaporator.
Check the door seal. Put some vaseline lightly on the seal all the way around the door. Close the door tight like you normally would. Open the door and check the inside frame. anywhere there is no vaseline means the seal is not making contact and sealing.
Check the product door to make sure it is closing all the way and lined up.
Check the drain tube. it should have a loop or crimp in it and preferably a little water to keep warm air from coming up the tube.
Check the spot with the tubes and electrical cables come thru from the compressor. make sure there is a nice tight fit and it is sealed with plumbers putty or electrical putty.

After all that Im stumped

Good Luck

Wow, snack dude pretty much just summed it up. Very knowledgeable.