Martin
sounds like the compressor has siezed but isn't pulling enough current to trip the fuse. maybe a 13 amp fuse where it should be a 5 amp.
Is the compressor making any sound? is the pipe leaving the compressor cold? is the other one hot? they should be. If both hot then its just heat transfer from the overheating compressor and your back at a siezed or part siezed compressor.
Is the fan for blowing air through the unit running? if not it doesnt cool the condensor coil, the compressor goes high pressure and overheats. It should shut itself down then though. If you have a pal with a clamp ammeter ask him to measure the current draw i'd expect about 3 amps the rating should be on the unit plate and if your drawing more than the rated current then its sayonara to your dehumidifier, its cheaper to replace than repair
kennyf
April 2009