404A Freezer Issue

[Lennyb]

I have a 404A split system walkin with line setts approx 30 ft, I have a box temp of 12 deg F and dropping. System Pressures are 25 PSIG Low side and 175 PSIG High side. 12 inches from Compressor I get a 45 deg F. When adding 404A the low side pressures temp and PSIG drop raising my superheat. Currently my superheat is approx 55 deg F. After de-Iceing evap coil and TXV and Selnoid valve I noticed TXV is frosting up imediately. I changed the selnoid coil and no change.
My thoughts are recovery refridgerant and change both TXV and selniod valve. Approximately 6 months ago the coil went bad on the valve... Any suggestions or thoughts???

[KickedGinger]

You have a low refrigerant charge.

[beenthere]

You have a low refrigerant charge.

looks that way.

[Dad]

55* superheat with a 12* box temp?

<scratches head>

[hvac wiz 79]

Your SOLENOID shouldn't be icing up. I am reading this right that you de-iced it right?

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[j3hvac]

Do you happen to have a sight glass installed? I'm surprised your box temp is 12 with that superheat.

[jpsmith1cm]

Moved thread to Refrigeration and Ice Making.



I think you're a little low on gas, too.

[Phase Loss]

low on gas, restricted drier, restricted TEV.

Do you have a liquid sight glass?

Need to dig deeper.

55* superheat and a 12* box is fishy

[drife678]

Is the coil still froze up. Make sure both sides of the coil are free of ice.

[Lennyb]

Is the coil still froze up. Make sure both sides of the coil are free of ice.

Sight glass yes, no bubbles....
Selnoid was frozen up because the whole side with TXV, seloid, and fan delay all were under a solid block of ice.

[Lennyb]

Both sides of evap coil were cleared.

[ar_hvac_man]

Make sure the coil is completely clear of ice. Many times once you get the back clear you will still have ice on the front. Measure your SH at the evaporator.

Does the unit have an accumulator? There will be a very large diff in SH if you measure the line going into the accumulator and the line coming out and going into the compressor.

[beenthere]

Whats the ambient temp at the condenser.