Chosen Solution
Hi: I have the Keystone Dehumidifier Model KSTAD70B, it is very similar to the ‘A’ version. It has recently started icing-up and it appears it will run the compressor even when the fan is shut off. In fact, recently while it was seeming to run normally (cycles always start OK) I tested it by pressing the power button on the top panel, the lights went off as did the fan but the compressor just kept going. Per the ‘block’ schematic on the machine it would seem it is the power relay sticking that would cause this problem. Has anyone else had this issue? Eventually the compressor does shut off but only after it gets really hot . Is the relay the likely fix? I`ve already ordered a couple on ebay for $3 to try. Thanks! Tom
Hi: To fix my unit I did replace the power relay but I really believe the fix was simply cleaning the contacts of the sensor that fits in a holder in front of the fins. From the back mine was on the left side. It was during my 2nd attempt to fix mine that I realized the connector & pins for the sensor are of poor quality, they should be gold plated. After using “Deoxit Gold” on the contacts the unit has run without further issues. If you need more detail for finding the connection (in the steel covered box) please let me know and I will see what I can dig up. I also have a second power relay I bought if you want to try that route. Tom
Very nice troubleshooting based on the block diagram. I would say that if it seems to ice up sooner than expected that the Freon is getting lower as this is a visual symptom to “Low on gas”. I would also say that the fan kicks off due to the low temperature due to the icing and the heat exchanger does not need cooling off by the fan. I also would guess that your relay is stuck closed but a good smack on the head should rattle its brain to let loose and shut down as expected for additional troubleshooting, give it a good rap. Icing due to low gas or very high humidity and also give it a good cleaning as dust will help condense water that will not drain off like normal, the dust will attract the water and it will freeze due to low fan air flow being blocked by the dust again. Then due to your constant compressor running will cause the temp to drop as well. So we will assume the overtemp switch is working as the compressor is shutting down when overheating, this will override the stuck power relay.
