Granby KHM-1/090, Installation, Operation And Service Manual

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Step Possible Cause Check-out procedure Corrective action
No Cooling
7
Blower .
High speed
Check for 24 Volts between
G and C on electronic fan
control
Yes - Move to next step
No - Check thermostat and wiring; if it's
OK, then change the electronic fan
control
Check for 120 Volts at the
''COOL'' terminal of the
electronic fan control Yes - Check ''COOL'' speed on the
blower motor
No - Change the electronic fan control
Step Possible Cause Check-out procedure Corrective action
Electronic air filter and Humidifier
8 Condensing unit
Check for 24 volts between
terminal Y and C on the
electronic fan control
Yes - Compressor ON
No - Check thermostat and wiring
9 Electronic air filter
Check for 120 Volts on
terminal ''EAC'' of the
electronic fan control
(thermostat must call a Heat,
Cool or Fan ON demand
Yes - Electronic filter failure
No - Change the electronic fan control
10 Humidifier
Check for 120 Volts on
terminal ''HUM'' of the
electronic fan control (burner
must be energized)
Yes - Humidifier failure
No - Change the electronic fan control
7.0 SERVICE
REGULAR MAINTENANCE
Check complete operation at least once a year. In Canada see B139, (Maintenance), in
United States see NFPA 31, for recommended servicing procedure. Clean flue pipes on a
regular basis. Replace flue pipes if there is any sign of corrosion or other problems. Gaskets
should be checked and may have to be replaced.