Hi everybody

We have a small portable dehumidifier in the basement. In the beginning (a few years back) everything was as expected but now there is heavy ice buildup on the right side of the coils.

It is a very simple device. The air goes in, travels through some cooling coils, then through a heat exchanger and then being blown out by the ventilator. The compressor sits below.

I have in mind, that in the beginning the air condensed evenly over the wound coils and nice droplets of water condensed. But I'm not sure (braincell problem).
But now, there is heave ice build up on the right side of the coils (on perhaps three pipes of say...15 in total over the whole width of the air entry). The ice never reaches the temp sensor and builds up and up, and up. So long, the hole where the water can flow down is locked. At some point, it realizes to defrost but then the water can not flow down. You can imagine the mess on the floor. During this, on the left side no condensation occurs.

So the ice blocking the hole is a secondary problem. I solved this by installing a Temp-Switch device which intercepts the "water full" sensor which is a simple switch. So, If it has too much ice the device thinks "water full" and switches off. Later on, my temp sensor switches back an the device continues to run. So I no longer have the water mess, but it seems to me the water should not build ice to this amount and condensation should occur over the whole width.

Attention (!) the following is a amateur theory:
Can it be some oil is blocking the pipe? Should I lay the device on one side for a while so the oil can flow back? But on which?

It is a cheap device, yes. And I could buy a new one, yes. But I would prefer repairing it. Don't like the throw away mentality.

Thanks for any tips
Hotzenplotz