Answer: This error may occur under the overload due to clogged air filter of the optional vacuum unit, or at the maximum vacuum strength volume of 65.
1. Turn off the main power supplies of the main unit and vacuum unit, and then remove and clean the air filter.
① Remove the air filter as shown in the figures.
② Remove dust sticking to the air filter.
2. Wait about five minutes since the main power supplies of the main unit and vacuum unit are turned off. Then restart them.
3. If you are using the vacuum unit at the maximum vacuum strength volume of 65, lower the blower rotation frequency panel indication to 60.
At maximum 65 (* The volume is turned to the right-most end as shown in the figure.)
4. If the error occurs again after following the above 1 to 3, check the indication on the blower rotation frequency panel, and then please contact service.