Had a Ultra-Aire 98h installed last spring (2021) for shoulder season dehumidification. Worked great through spring, fall, winter, and this last spring. It has sat off most of/all of the summer, but as things are finally starting to cool a little its starting to run some.
It doesnt seem to be dehumidifying much/at all. Heres some info:
-House is spray-foamed/conditioned attic, all hvac equip is in attic,dedicated return for dehu, supply goes into air handler supply plenum
-run by ecobee thermostat, set to keep at 50% (house is set at 78 during day and 72 at night, AC handles humidity just fine when it runs)
-dehu unit fan and compressor kick on and off when thermostat tells them to
-clean/new air filter
-condenser and coils seem to be working,visual and infrared thermometer checked
-two distinct lines of ice build-up at top and middle coils
-defrost cycle maybe working? Heard compressor kick off, good amount of water dumped through drain line, ice had definitely lessened, then compressor kicked back on
*Ive got a calibrated temp/humidity sensor on one of the supply registers – used that sensor to track info for the last 1+ year. Would routinely see it pumping out dry warm air on sensor, now its slightly warm air with humidity not much below room/house humidity (It used to get upper 80s temp/low 40s/uppers 30s humidity, now temp is low 80s and lowest humidity Ive seen from it is 47%. I know dew point is the better measure – its pumping out a higher dew point than the house is currently at.)
Not sure how to troubleshoot this. Can call company who installed it, but I dont now that they have much experience with these units other than installing them. Dont want to do any DIY just not sure where to start. Any help would be appreciated.