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Servicing should only be performed by a Qualified Service Technician
Service Note:
The 5 pin PWM signal plug MUST remain plugged in to the 5 pin socket on the blower assembly at all
times (BTH 120-250 Models only). Disconnecting this plug will cause the Combustion Blower to stop. If the
electronic speed control is functioning properly Combustion Blower speed should noticeably reduce during
the Trial For Ignition operating state. If blower speed reduction does not occur during the Trial For Ignition
operating state ensure the 5 pin plug from the CCB is securely plugged into the matching 5 pin socket on
the blower assembly and that the J5 plug is securely plugged into the J5 socket on the CCB circuit board.
Perform a close visual inspection of the pins inside the plugs and sockets at the Combustion Blower and the
CCB, replace any worn or damaged wiring harnesses as necessary.
BLOWER MOTOR
AND ELECTRONIC
SPEED CONTROL
COMBUSTION BLOWER ASSEMBLY (BTH 120 - 250 MODELS)
BLOWER
HOUSING
3 PIN
WIRING
SOCKET
5 PIN
WIRING
SOCKET
