What to do when an ear has been clogged for days but there is no pain or fever?

It is most likely an excess of ear wax. You want to see an ear nose and throat doctor, they have great tools for extracting the excess wax.

Hold your nose, and breath, and blow GENTLY. Then try putting a few drops of hydrogen peroxide in each ear. Of course, you should keep the amount of pressure within reason, lest you risk damaging your ear drum. If the ear is full of wax, then you may wish to begin by using an ear candle. This will require the assistance of a partner. There is a possibility that you have a dead insect in your ear, and you may need assistance from a regular doctor in removing it.

You can also do what's called a brainflush or wash not sure of the term. The way to do this is to run a bath soak for awhile, take one of the blue syringes you would use for a baby to clean their ears or nose, fill it with water, and with the ear submerged flush the warm water through your ear as many times as you need to. You just have to make sure the water isn't to hot for your inner ear. I lost complete hearing in my left ear because it was clogged, the ear candle, peroxide, etc., did not work for me, this did. Also make sure it's the blue syringe with the long kneck so it will fit comfortably in your ear, test the water on your wrist just as you would for a bottle.