Lennox Fhm 170 Installation, Operating And Maintenance Guide

MAINTENANCE DIAGNOSTIC
FLEXYII_WSHP-IOM-1307-E - 75 -
INDOOR FAN BLOWER
FAULT POSSIBLE CAUSE AND SYMPTOMS SOLUTION
High amps on action Fan motor
Pressure drop in the ducting installation
too low.
Reduce the rotation speed of the fan
Measure and estimate the airflow and
pressure and compare with the
specification from customer.
High amps on reaction Fan motor
Pressure drop in the ducting installation
too high
Reduce the rotation speed of the fan
Measure and estimate the airflow and
pressure and compare with the
specification from customer.
Unstable running and high
vibration
Fan jumping from one operating point to
the other
Change rotation speed of the fan
OUTDOOR AXIAL FAN
FAULT
POSSIBLE CAUSE AND SYMPTOMS
SOLUTION
Heat Pump mode:
Circuit breaker open
High Amps due to a low voltage from the
main supply
Check the voltage drop when all
components are running.
Change the circuit breaker for one
with a higher rating
High amps due to freezing of the coil
Check the adjustable amps on the
motor starter.
Adjust the defrost cycle set points
Water ingress in the motor connection
box.
Change the component
ELECTRICAL HEATER
FAULT POSSIBLE CAUSE AND SYMPTOMS SOLUTION
High Temperature trip out on
electric heater
Low airflow rate
Measure and estimate the airflow and
pressure and compare with the
specification from customer.
Incorrect position of the Klixon
Check that the Klixon, is positioned in
the airflow, relocate Klixon if
necessary
Check that there is no heat transfer
from the Klixon support.

Lennox Fhm 170 Specifications

General

Brand	Lennox
Model	Fhm 170
Category	Heat Pump
Language	English