Refrigeration noise and cooling problems

[bil10219]

I have a DN501 which was not cooling. I have had problems with it before either not cooling or freezing up. These were fixed by turning it off over night and plugging it back in. This time I replaced the thermostat and it seemed to be cooling OK but it was making a ton of noise from the compressor. The customer complained about the noise. Any ideas on this? Also, if it is still not cooling, what is the best route for getting a replacement compressor?

[Paraflier]

My heat pump was doing the exact same thing (Same principle, only a larger scale.) last summer.

The O/S unit would run and run and run, thus freezing my fins, and blocking my thermostat, so the I/S unit would think it needed to keep running. Kind of a vicious circle.

Turns out my coolant lever was pretty low, and needed to be recharged. Got some cold-juice in my lines, and bingo. No more problems. So... possibly recharge with cold juice.

The noise? You got me there. Could be a ghost....?

[bil10219]

Thanks for the reply  But, Wouldn't that imply a leak?  In Mass, I think you need a license to buy refrigerant. I'd love to be able to try that but if I have to hire a refrigeration guy  - by the time I'm done - It would probably be less costly to buy a reconditioned deck and just install it. Unless I was sure that the shot of juice  was what it needed.

[Quarter Master]

Bil,

            If the compressor is noisy, IMHO, you'd be better off getting a refurb or new complete deck if you feel overall the machine is worth it.The owner is already not happy with the noise.Don't want to get kicked out.

[Technivend]

Thanks for the reply  But, Wouldn't that imply a leak?  In Mass, I think you need a license to buy refrigerant. I'd love to be able to try that but if I have to hire a refrigeration guy  - by the time I'm done - It would probably be less costly to buy a reconditioned deck and just install it. Unless I was sure that the shot of juice  was what it needed.

In MA you do need to be certified to by refrigerant.

But to diagnose, what is frozen when it freezes? The whole evap coils or just the right side or just the product?

As far as the noise, have you pinpointed it to the compressor itself or could it be the evap fan? If the evap fan is not spinning correctly and the coils are dirty it can simulate a low charge in your unit. You can check the noise easily enough but you need to take precautions. Put on heavy gloves, turn off the thermostat so the compressor and fan stops, reach around and hold the fan and then turn on the thermostat. The only noise you will hear is for the compressor at this point. If you hear the noise it is your compressor, if not let go of the fan and see if that makes the noise.

[bil10219]

Thanks to all for your help. It only froze once in the hot days of summer. The whole bottom was frozen but it looked to be thicker on the right hand side near the copper tube.

If I do need to replace the unit - any suggestions on the best buy on a reconditioned unit?

Thanks again.

[Technivend]

Thanks to all for your help. It only froze once in the hot days of summer. The whole bottom was frozen but it looked to be thicker on the right hand side near the copper tube.

If I do need to replace the unit - any suggestions on the best buy on a reconditioned unit?

Thanks again.

If it only froze once and it was all the way across I wouldn't worry about it being low on gas. Try to isolate the noise first. If it is in the compressor it could be all one problem.