1. Use the pump PURGE button to reduce the water level in the reservoir.
2. Stretch the hose flat to drain it completely. Raise one end above your head and spool hose while draining water out the other end.
3. To reduce biological growth flush the unit with a bio-fungicide that is approved for use with copper, aluminum and polyethylene. To flush: a. Run the hose to a drain. b. Plug in the unit but do not turn it on. c. Remove the air filter. Slowly pour a quart of the antimicrobial through the heat exchanger d. Hold in the pump purge switch to reduce the water level in the reservoir. e. Flush with water.
4. If the unit will be exposed to freezing temperatures, after purging, take off the upper housing and pour 1 cup (8oz) of a propylene glycol-based anti-freeze through the heat exchanger. It will flow down into the pump reservoir. Do NOT purge the solution out of the unit.
5. Dirty filters should be changed prior to long-term storage to prevent biological growth on the filter.