# Need some help on walk in freezer



## jmyhvac (May 16, 2012)

Been working on a walkin freezer, this is a 404a system, the problem is the coil has to much ice build up and running to warm I had problem with defrost control got that fixed coil problem and got that fixed. I put my gauges on today and put small charge to it I was running 150 head and 10* coil with 20psig. cooler was coming down, went back 6 hours later and running 160 head 20* coil 15psig with the cooler running38* inside I still have to much ice buildup I have it defrosting every 6 hours for 40 min. temp. control is set at 10* any ideas would be greatful. I work on hvac more than refrigeration. Thanks. Went up this morning and unit running good, down to 10* inside cooler but still have to much ice build up on evaperator do I need to go to 4 hours defrost or could there be something else going on?


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## artco (Oct 3, 2010)

Are the gaskets on the doors not sealing well, allowing warm humid air in?

Is someone going in and out more often?

Does the customer keep the doors open when doing inventory?

I assume the condenser and evaporator coils have been cleaned.


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## jmyhvac (May 16, 2012)

Yes, I checked all that and all of that is going on I had a hard time figueing this one out, what it was is someone put the wrong size plunger in the valve body now I have the freezer running at 15* on 3 defrost per day and it running perfect now.


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## Ahh-Cool (Jun 30, 2012)

How did you figure that out? what made you look at that?


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## jmyhvac (May 16, 2012)

After checking all controls and knowing they work the coil was the only problem when I took it apart and cleaned it, it still would not shut down even when I put the new plunger in the body, I seen the old body was larger and the plungers were the same size so putting in the new body is all it took.


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## Ahh-Cool (Jun 30, 2012)

thanks for replying


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## brian p (Feb 24, 2013)

What the hell is a plunger? Do you mean an orofice? And 15 degrees is not good. You should be looking for 0 to 10 below.


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## FanAttic (Jan 5, 2012)

He is probably talking about the pumpdown solenoid not sealing to shut down shut off compressor that contenues to run forever and build ice. I would have guessed there is some sort of restriction and the unit is undercharged, fooling by the higher suction pressure.


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## jmyhvac (May 16, 2012)

The valve body was larger then the plunger I changed the valve body and charged it and the problem was fixed come to find out the hvac company they were using sabotaged alot of different things so they would have a lot of call backs I been through all there equipment and found many problems


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