ice merchandiser not freezing

[budmanr224]

Hi all, I have an ice merchandisers not freezing right, I have changed the compressor, drier twice, txv, condensor fan motor, thermostat, &cleaned the coils, and still not freezing, 40 degrees, also the comp is shutting off on high head pressure (400 psig). What else can I try? Thanks for your help

[Yuri B.]

If it has one, maybe the solenoid valve is not opening ?

[monkey spanners]

Overcharged? Would give high head and can stop suction getting low enough to freeze.

Superheat and subcooling, air on and air off temps would give more idea of whats going on.

[budmanr224]

Doesn't have solenoid valve, proper weighed in charge. However while running, the suction line is cold and about half of the evaporator coil is getting cold but the bottom half is not. Could the evaporator be clogged internally and be causing the high pressure?

[install monkey]

was it vacced out with a torr gauge, non condensables, is txv bulb insulated ,correctly mounted, maybe a bigger orifice

[budmanr224]

Yeah, vacced for abt 20 min, txv bulb is mounted and covered, and its lines are frosting up in front of the evap. But part of the coil is just not getting cold

[Magoo]

What refrigerant is in system, weighed in as liquid or vapour.

[RANGER1]

With the limited amount of info like pressures,temps, superheat, my guess is TX valve problem.
Either blockage or power element has/is loosing its charge.
With maybe liquid banking up in condenser.

[budmanr224]

It is 404a, 2 lbs, charged as liquid, when I changed the txv, strainer was very clogged, didn't measure the specific temps though other than the overall temp in the box

[budmanr224]

Pressure was 40 psi suction and shutting off at400 psi head pleasure

[RANGER1]

budman,
Where are you measurig discharge pressure?
Can you measure it on inlet & outlet of condenser to see if there is a blockage?

Can you blow nitrogen through evaporator also to see if any restrictions.

[budmanr224]

Measuring at a service port between condenser and compressor, blew nitrogen on and it came out slow like it was being restricted but nothing else came out like oil or junk but seems like something in there

[RANGER1]

Measuring at a service port between condenser and compressor, blew nitrogen on and it came out slow like it was being restricted but nothing else came out like oil or junk but seems like something in there

So what will you do next???

[budmanr224]

Pull the evaporator I guess, was hoping there was another way though, but I guess that is the problem. Sorry, I am a new tech, learning on the Job

[dchappa21]

Do you have a receiver?? Do you have a sight glass? If so is it full?

[kiwi]

I'm glad I'm not your customer. Why did you change the gear you list if you do not know why?
My first suggestion would be to come back with a superheat @ the evaporator.

[SOKAL GUY]

A kiwi ur not helping with rude comments

[panchovaz]

Do you check? the cpr valve most the equipment with 404a use cpr valve and is very importat be sure your equipment is no overcharge, because the cpr valve don't works good, i tell you for some bad experiences, i hope you got some way to fix your problem dude.