Daewoo FRA-U20ICB Fridge freezer

[Mickey Leeke]

The fridge freezer began icing up. Going through the possible reasons, I found that the unit was not going into defrost mode where the compressor and fan motors were disabled and the evaporator heater turned on. The D-sensor, F-sensor, R-sensor and heater element all tested okay. Doing a forced defrost brought on the defrost heater for several minutes. Everything points to a faulty ECU, but it has proved impossible to source a replacement 30143H4070/ FRU-579IEE8NI pcb.
To bypass all this, I connected the evaporator heater directly to an external plug-top timer and parallel connected a double pole relay through which I connected the power supply to the fridge freezer through the volt-free N/C contacts.
When the plug in-timer operates once daily for thirty minutes, this powers up the evaporator heater and energises the relay, opening the N/C contacts and disconnecting the power to the fridge freezer. At the end of the timer period, the relay drops out and power is restored to the fridge freezer. I will monitor the build up of ice on the evaporator to find the most suitable time periods for the evaporator heater to be turned on.
Can anyone assist in identifying the initial fault and/or comment on my possible solution.

 

[Diver300]

You should keep an eye on the fridge temperature. Is that still being controlled? It would be be easy for that to get too cold.
I suspect that once a day is more often than you need for defrosting.

 

[ahsrabrifat]

The fridge freezer began icing up. Going through the possible reasons, I found that the unit was not going into defrost mode where the compressor and fan motors were disabled and the evaporator heater turned on. The D-sensor, F-sensor, R-sensor and heater element all tested okay. Doing a forced defrost brought on the defrost heater for several minutes. Everything points to a faulty ECU, but it has proved impossible to source a replacement 30143H4070/ FRU-579IEE8NI pcb.
To bypass all this, I connected the evaporator heater directly to an external plug-top timer and parallel connected a double pole relay through which I connected the power supply to the fridge freezer through the volt-free N/C contacts.
When the plug in-timer operates once daily for thirty minutes, this powers up the evaporator heater and energises the relay, opening the N/C contacts and disconnecting the power to the fridge freezer. At the end of the timer period, the relay drops out and power is restored to the fridge freezer. I will monitor the build up of ice on the evaporator to find the most suitable time periods for the evaporator heater to be turned on.
Can anyone assist in identifying the initial fault and/or comment on my possible solution.

Keep a temperature logger in the fridge/freezer to ensure the defrost cycles aren't raising temps too much.
Consider a bi-metal defrost thermostat in series with the heater if you're concerned about safety—it will cut power if temps rise too high.

 

[rjenkinsgb]

There is a service manual for the general series (including the same control board) here:

DAEWOO FRU-541 SERIES SERVICE MANUAL Pdf Download

View and Download Daewoo FRU-541 Series service manual online. FRU-541 Series refrigerators pdf manual download. Also for: Fru-571 series, Fru-547 series, Fru-577 series, Fru-549 series, Fru-579 series, Fru-54b series, Fru-57b series, Fru-54g series, Fru-57g series, Fru-54l series.

www.manualslib.com

Check pages 12 - 14 re, defrost conditions & tests?

My freezer (different make) started icing up due to the door gasket stiffening up and no longer sealing properly. A new gasket cured it completely.

 

[starLED]

My freezer (different make) started icing up due to the door gasket stiffening up and no longer sealing properly. A new gasket cured it completely.

Which was probably pricey.

 

[Nigel Goodwin]

Which was probably pricey.

But it repairs it properly, and stops a LOT of wasted money.

It's also why you shouldn't swap your door opening direction (even though most are designed to be swapped), as the seal has already been set to open in the other direction, and if you swap it over it might not seal properly. If you have to do it, either replace the seal at the same time, or try warming the old one with a hair drier

 

[rjenkinsgb]

Which was probably pricey.

Around £20 on ebay. I was given the fridge and freezer, already some years old, soon after I moved here ~25 years ago, so not much to complain about!

The original seal was like rock and cracking up. I reset the door height to allow for wear and align the new seal better, but I didn't change the direction. I originally positioned the two units so the doors open away from each other, which works well.

 

[starLED]

Around £20 on ebay.

You gotta a good deal.

I was quoted 50 euros for seal and 40 euros for replace.

I agreed neither.