General Assist Technical Reference

CMTA and KMTA Spitting Water

Serial number identification for units with the revised coil treatment
Use the serial number ranges below when investigating water-spitting reports on applicable CMTA and KMTA indoor units.
Technical reference: The serial numbers below identify the production point from which the new coil treatment was introduced for each listed model.

Applicable models and serial ranges

#Indoor unit modelNew coil treatment from serial no.
1ASTG30CMTBT000076 and later
2ASTG34CMTBT000081 and later
3ASTG30KMTBT002226 and later
4ASTG34KMTBT001501 and later
5ASTG30KMTAT026262 and later
6ASTG34KMTAT016735 and later
7ASTG30CMTAT003761 and later
8ASTG34CMTAT002101 and later

How to use this information

  1. Confirm the exact indoor unit model.
  2. Locate the unit serial number on the rating label.
  3. Compare the serial number with the applicable threshold in the table above.
  4. If the serial number is at or above the listed number, the unit was produced with the new coil treatment.
  5. If the serial number is below the listed number, the unit predates the stated coil-treatment change.
Important: This reference identifies the coil-treatment production change only. The supplied information does not provide a complete diagnostic procedure or confirm that every water-spitting complaint is caused by the coil treatment. Normal installation, drainage, airflow and operating-condition checks should still be completed as applicable.
Technical reference prepared from the supplied CMTA/KMTA serial-range information. Confirm model and serial number before applying this information in the field.