Sullair SD-220 - User Manual

Questions and Answers

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Leslie LeeAug 17, 2025
What to do if the dryer does not switch towers in Sullair SD-220 Dehumidifier?
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  Wendy BaileyAug 17, 2025
  If your Sullair Dehumidifier's dryer isn't switching towers, several factors could be at play. The inlet valve combination might not be opening or switching; in this case, check the electrical functioning of the solenoids and replace either the solenoid or the complete valve combination. Another reason could be that the PLC isn't functioning; check the PLC and the fuse in the control cabinet. The vessel might not be pressurized; check whether the blow-off valves are dirty and replace them if necessary, and check the electrical functioning of the solenoids, replacing either the solenoid or the complete valve combination. The regeneration orifice might be obstructed; clean or replace it.
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Jessica RichardsonAug 25, 2025
How to fix high back pressure during regeneration phase in Sullair Dehumidifier?
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  Jacqueline JacksonAug 25, 2025
  High back pressure during the regeneration phase in your Sullair Dehumidifier can stem from a few issues. The silencer might be blocked; clean or replace it. The inlet/exhaust valve cylinders could be defective; lubricate the cylinder, replace seals if necessary, or replace the cylinder. Also, the check valves might not be sealing; repair the check valve.
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Pamela GarciaNov 8, 2025
Why is the dew point too high in my Sullair SD-220 Dehumidifier?
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  amy92Nov 8, 2025
  If the dew point is too high in your Sullair Dehumidifier, it could be due to several reasons. The operating pressure might be too low, or the air flow capacity might be too high; in this case, increase the operating pressure and reduce the air flow capacity. Another cause could be that the air inlet temperature is too high; reduce the temperature, or connect an air cooler upstream. Also, the differential pressure at the pre-filter might be too high; check the filter element for impurities and change it if necessary. The condensate drain might not be functioning; check its operation and replace it if needed. The desiccant could be soiled or have disintegrated; check the pre-filter for impurities, change the filter element, and replace the desiccant, disposing of the old desiccant. The volu...
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Matthew RhodesDec 3, 2025
What to do if my Sullair Adsorption Dryer does not switch over?