I hear a rattling noise behind the fan, possibly in the motor itself. Runs then fan stops...

Verify the humidity reading with another device. Perhaps the humidity sensor is dirty or bad.

Another possibility is the switching device that runs the compressor and fan is shorted. If it's a mechanical relay, the contacts may have welded together, or if it's a solid-state relay, it's got a punch-through or meltdown in a device junction. My guess is it's a mechanical relay since you mention it used to click on and off and now you don't hear that. The relay may be on the control board, or it may be mounted separately - I don't have a photo or diagram of the inside of your model available.

the "noise" you hear is most likely the rattle of the evaporator coils as that's where the "old fridge" sounds come from , i'll bet there was little rubber shock insulator collars around the coils of tubes in there holding them still , but now the rubber is hard and cracked allowing the coils to hit one another producing the noise you hear , Rubber bands could be used as a substitute but would sucome to the same folly eventually over time and break requiring you too reapply new ones

the problem is dry bushes on the fan shaft. It is best to replace the fan motor unless you have a good appliance electrician who can pull the motor apart ad knows how to lubricate the bushes.

mcdevito75 here, It could be the capacitor if you can replace with same size do so. The Armature or communtator in the motor could be shorting also, do the capacitor the change the motor.

A dehumidifier is basically an air conditioner, so some coils should feel hot, the others should feel cold.

If no water is collecting, then the unit's compressor is not starting. Typically you have four possible failures causing this: the switch/wiring for the compressor has an open circuit, the motor-start capacitor for the compressor has failed, the compressor itself has failed, or all the refrigerant has leaked out.

If there is evidence that it is 'trying to start', but then clicking repeatedly, this can be a symptom that the refrigerant has leaked out, as some devices have a pressure switch to prevent compressor damage.

Also, a failed start-capacitor can also cause the click-click noise if the device has a current limiter switch on the compressor.

So the short answer is, it's broken :)

It sounds like the fan has etached from its hub. This usually is not repairable if that's the case. Replace the fan.

I have no experience of your particular machine but I have some experience of my Wood's DS-15, another fine machine of the compressor type that is built to last. They should be rather similar in design.

My first thought when I read your problem description is that you have a severe buildup of dust inside the machine. On the Wood's, you loosen the front grill and behind it you will see the fan, behind the fan is the condenser pack, and then you get to the evaporator coils that are visible from the back of the machine.

Maybe the configuration is slightly different on your machine but they are built very simple these machines, easy to see what they need in order to work as designed and you already know the most central and expensive parts seem ok.

I had some problems with low efficiency on the unit after six years daily service in a laundry room for drying clothes, took it apart and couldn't believe the amount of dust that was packed into the fine fins of the condenser on its back side! Also extremely much dust on most components like the fan.

I just took it outside and blew it clean from the front side with compressed air, problem solved and machine performance went back up to where it was when new!

I would imagine after a few more years of dust buildup inside, at one point or another the dust will reach the fan and prevent it from spinning. It is also possible of course that the fan motor is shot but I'd start with a really good cleaning.

If that doesn't help I'd continue with the multimeter see if the humidistat gives power to the fan and compressor when it should, if the fan actually spins when powered, if the switches work. It should be quite easy to track down the reason the fan doesn't spin, IMO. I believe you can buy replacement humidistats and motors if they turn out to be faulty.

Good luck!

dehumidifier motor making rattle noise

I HAVE HAD A COUPLE OF UNITS THAT HAVE KEPT THE FAN RUNNING ALL THE TIME. I REPLACED THE CONTROL AND THAT TOOK CARE OF THE PROBLEM.