[I've cross posted this to what seemed to be the most appropriate places;
no flames please]
I have a 4-year old Kenmore 65-pint dehumidifer which sits in a basement
room containing electronics, etc. and I keep the relative humidity below
50%. It has functioned well until I turned it on for this summer season
(in the winter, hot air from the furnace keeps the room dry as a bone).
Nothing has changed in the room, or the basement, which would affect the
ease with which humidity could leak back into the room.
I keep a digital thermometer/hygrometer in the room (double-checked for
accuracy with another unit elsewhere in the house). The problem seems to
be the (digital) humidistat (which has a range of 40 - 60%) which now
seems to be about 10 - 15% too high. As a result, even with the dehumidifer
set at 40%, the steady-state humidity in the room barely goes below 50%.
I checked the warranty and it only applies to the sealed components
(condenser, compressor, etc) so I opened the unit and found no evidence of a
humidistat adjustment or trimmer. The humidity sensor is mounted on the
inner frame of the unit, within the stream of air flow between back to
front, next to the sides of the coils. When it has stopped running at an
ambient humidity of 50% (even though set to 40%) it restarts again when I
blow moist air from my mouth at the sensor.
It looks to be sourced from LG, and browsing in stores I see newer units
which allow set points down to 30% relative humidity, as well as low
temperature operation. I'm toying with the idea of simply replacing the
unit, but wonder if it's worth the expense of having a non-warranty
failure repaired - or the hassle of ordering a replacement sensor and
trying it myself.