True T-49 refrigerator/freezer temperature calibration

Did someone attempt to charge this unit with refrigerant?

The old gasket just pulls directly out from its slot in the door. Start about 3" away from a corner, then pull the corner out; the rest is easy. Soak the new gasket in warm water before fitting; it softens the edge and makes it easier to push in.

Things to check are:

Is the thermostat set to the correct temperature (Low, Med, High)?
Are the door seals in good repair and making a good seal with the freezer cabinet frame?
Is the door warped or distorted in any way, will lead to leaks.
Can you hear the compressor/motor running?

What gas is it on? R404a 12 -14 psig

Hi, what is the name and model of the freezer?

You have non-condensables in the system.

1.Recover Refrigerant

2.Change Drier

3. Evacuate to 500 Microns

4. Weigh in charge

most freezers have 2 controls. 1 is a defrost terminator and the other is a fan delay. the delay and the defrost terminator can sometimes be a "2 in 1" type switch. you would have to study the wiring diagram. The delay will not let the fans come on untill the evap reaches a preset temperature. take another look at the diagram. It may be that the evap is not getting cold enough. you may have a refrigeration issue.

There are three main reasons the fans would not come on.
1: A bad door switch. There are switches on the top part of door frame. They turn fans off when door is opened to prevent warm air from being drawn into unit when door is open. If a switch goes bad the fans will never turn on.
2: Refrigeration problem. The fans are tied into a temperature switch called a fan delay. The fans will not come on until the coil is well below freezing. This is to prevent water spray after a defrost. If unit is low on gas or has any other cooling issue the fans will not come on.
3: Bad fan delay switch. If the fan delay switch becomes "stuck open" the fans will not be energized.

Feel the back of your evaporator coil, if it is very cold and frosted you probably have a bad fan switch, or a bad door switch. ;)

The pressures depend, somewhat, on the expansion device,i.e. a TXV or Cap Tube. Take a pressure reading, then convert it to a temperature. The evap temp should be right at 10 colder than the box temp. Remember, heat flows to cold so the evap has to "Lead the Load" in order to cool. In many cases, the condensing pressure is usually ambient temp, plus 30, then convert to a pressure. These are general accepted practices that have been used for many years.

Hope this helps

The alarm is set off when the freezer is out of the differential range of the setpoint. In other words, the freezer is still too warm. If you press the alarm button, the sound will stop but the light will stay on. If the unit is working correctly and cooling properly, this light should go out once the cabinet temperature gets close to the setpoint temperature. Hope this helps you.