ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL
CONTROL SYSTEM UNRESPONSIVE
DISPLAYED MESSAGE | CHECK/REPAIR | |
CONDITION/INDICATES | ||
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UIM Display Is Blank | • Ensure the on/off switch is on and working - | |
| replace switch if defective. | |
On/Off is turned off | • Check communication cable connections at | |
Water heater is not plugged in | UIM’s J2 Socket (page 27) and the CCB’s J16 | |
Tripped Breaker - Blown Fuses | Socket (page 36). Secure power and install a | |
120 VAC power supply problems | new comm cable. (standard Cat 5 network | |
24 VAC power supply problems | cable). | |
Defective transformer | • Closely inspect communication ports on CCB | |
Wiring or plug/socket connection problems | ||
and UIM for damage or wear. | ||
UIM communication cable problems | ||
• Ensure 120 VAC power is properly connected in | ||
Important Service Reminder: | ||
the junction box on the back of the water heater. | ||
When performing any troubleshooting steps outlined | • Ensure 120 VAC is supplied to CCB’s J3 Socket | |
pins 1 & 3. Hot wire to pin 1, neutral wire to pin 3 | ||
in this service manual always consider the wiring | ||
(page 36). | ||
and connectors between components. Perform a | ||
• Check 120 VAC to transformer primary winding | ||
close visual inspection of all wiring and connectors | ||
to a given component before replacement. | at CCB’s J1 socket pins 1 & 3 (page 36) with J1 | |
Ensure wires were stripped before being crimped in | plug removed, power on. | |
• Check J1 plug and J1 socket on the CCB for | ||
a wire connector, ensure wires are crimped tightly in | ||
wear or damage. Ensure plugs and sockets are | ||
their connectors, ensure connection pins in sockets | ||
mating properly and providing good contact. | ||
and plugs are not damaged or worn, ensure plugs | ||
• Check for 24 VAC from transformer secondary | ||
and sockets are mating properly and providing good | ||
contact. | winding at CCB’s J1 socket pins 4 & 5 with J1 | |
| plug inserted, power on. If 24 VAC is not present | |
Failure to perform this critical step or failing to | AND the two checks above were performed and | |
perform this step thoroughly often results in | the results were successful - replace the trans- | |
needless down time, unnecessary parts | former. Check all wiring for shorts before power- | |
replacement, and customer dissatisfaction. | ing up the new transformer. | |
| • Call the technical support phone number shown | |
| on the water heater labeling for further assis- | |
| tance if the problem has not been corrected | |
| after performing the procedures outlined here. | |
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UIM is Inoperable | • Ensure Ribbon Cable from the Button overlay is | |
| inserted correctly in UIM J3 Socket (page 27). | |
UIM does not respond to any user input using the | • Call the technical support phone number shown | |
operational and/or Up and Down buttons. | on the water heater labeling for further assis- | |
Water heater may be maintaining water temperature | tance if the problem has not been corrected | |
after performing the procedures outlined here. | ||
at the last saved setting or may not be operating at |
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all. |
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Technical Literature Department | 42 of 52 | Ashland City, TN © 2008 |
Servicing should only be performed by a Qualified Service Agent |
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