Service Bulletin Index - Johnstone Supply

Publications 319/622-5511
Amana, Iowa 52204 Fax: 319/622-2837
Amana®
Caloric®
Menumaster®
Modern Maid®
Glenwood/Sunray®
Speed Queen®
TO: TO: TO: All Service and Parts Managers DATE:
DATE: DATE: March 15, 1996
SUBJECT:
SUBJECT: RHD Defrost Control Boards
NO: NO: CAG-390A-B
SUPERSEDES SUPERSEDES CAG-390
Under certain conditions, the Paragon adaptive defrost control used in the RHD model heat pumps may not defrost as
expected. This condition can be the result of electrical interference which can, in some cases, cause the board to
temporarily lockup. If this lockup condition is occurring, the control will fail to initiate defrost or to self test.
To correct this condition Paragon has released a new defrost control Amana part number 10865004. This board has
several software changes to prevent control lockup as described above. To reduce the possible perception of improper
operation due to heavy frost, two additional software changes have been made in the -04 control. These changes
include a maximum defrost interval of 3 hours rather than the 6 hour defrost interval used on previous controls. Also,
if the defrost sensor remains open for 6 hours or longer, the control resets itself to a 90 minutes defrost interval. This
means that after the defrost sensor closes the next defrost will be in 90 minutes, subsequent defrosts will be adaptive.
The 10865004 defrost control was released in January 1996 to correct the electrical interference condition. This
control has performed very well with no failures in our quality testing and field evaluations. This control has been used
for service parts since January and in production units with date codes beginning 9601. In our continuing effort to
improve quality and reliability we have made additional improvements to the control thus creating a new control part
number 10865005. These changes will enhanse the controls ability to adjust the optimum defrost time as required.
This is a running change to the control, there is no need to replace -04 defrost controls.
It is important to remember when using the test terminals to initiate a defrost, it may take up to two minutes before the
unit goes into defrost, (1 sec. test time = 3 mins. run time) and the 30/60 must be closed or jumpered. For additional
information on defrost control operation or troubleshooting, refer to the RHA/RHD service manual.
Adaptive defrost controls are designed to reduce the frequency of defrosts thus improving the operational efficiency
and reliability of the unit. It is normal to see a greater frost build up on these units than with time temperature defrost
controls. The additional frost accumulation does not decrease the overall efficiency or performance of the unit.
NOTE: TO PREVENT POSSIBLE DAMAGE TO THE DEFROST CONTROL, 24VAC MUST BE DISCONNECTED
BEFORE CHANGING THE DEFROST CONTROL.
FILING PROCEDURES:
IMPORTANT PARTS-SERVICE COMMUNICATION
If the defrost control (10865001, -02, or -03) on RHD model heat pumps, is replaced with a Paragon 10865004 or -05
Adaptive defrost control or the C6431001 time temperature defrost control (used on RHA model heat pumps) on units
with serial numbers prefixes of 9512 and prior, Amana will provide labor to replace the defrost controls as described
below. RHD's manufactured 9601 & 9602 will have the revised 10865004 defrost control installed, 9603 and later
production will use the 10865005 control. Units manufactured 9512 and prior, shipped after 3/8/96, will have the
revised defrost control installed from the factory. These units can be identified by the orange dot on the carton adjacent
to the bar code label.