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Table 16 — Energy Wheel Conservation
Table 17 — Gas Heater
Table 18 — Electric Heater
PROBLEM
POSSIBLE CAUSE
SOLUTION
Inadequate wheel performance
Incorrect wheel rotation speed
Check wheel rotation speed.
Worn wheel media or worn/out-of-place seals
Check wheel integrity and seals. Adjust and/or replace
seals.
Unanticipated entering air conditions
Check entering air conditions and compare to design.
Dirty media
Check media for dirt and clean.
Improper wheel rotation
Misaligned belts
Check drive belts for engagement with sheaves.
Improper motor operation
Check drive motor and drive motor wiring for proper
voltage.
Improper VFD operation
Check VFD programming.
Improper VFD sensor operation
Check VFD input sensor (temperature/relative humid-
ity) for malfunctioning.
High pressure drop
Unanticipated airflow
Check airflow and compare to design.
Dirty filters
Check filters and clean/replace.
Dirty media
Check media for dirt and clean.
Noise
Out-of-place seals
Check seals and adjust.
Worn bearings
Check bearings.
Misaligned belts
Check belts for slippage.
PROBLEM
POSSIBLE CAUSE
SOLUTION
Steady on - No operation
Internal control fault
One flash - Combustion airflow
fault
Faulty combustion blower
Check for 230V supply and tightness at fan connec-
tions. If no power, replace.
Airflow switch not closing
Airflow switch opened during operation
Two flashes - Flame with no call
for heat
Faulty gas valve
Check voltage to gas valve with thermostat off.
Valve should not be powered. If there is gas flow,
replace valve.
Three flashes - Ignition lockout *
Ignition control miscommunication
Reset ignition control by removing 24V power to
ignition control terminal 24VAC.
Dirty burners
Clean burners to ensure proper flame carryover.
Faulty spark igniter
Check if connecting lead or spark igniter are dam-
aged. If yes, replace.
Faulty flame sensor
Check if connecting lead or flame probe are dam-
aged and/or touching earthed components. If yes,
replace.
Incorrect gas pressure at gas valve
Check that the gas pressure at inlet of valve is cor-
rect for the gas type. If not, correct pressure prob-
lem.
Faulty gas valve
Check that the gas pressure at outlet of the valve
rises when valve turns on and returns to zero, or
lower, when valve turns off. If not, replace.
* LED flashed on for 0.25 seconds and off for 0.25 seconds during fault condition. The pause between fault codes is 3 seconds.
PROBLEM
POSSIBLE CAUSE
SOLUTION
No heat
No call for heat
Check that the controls are set to call for heating.
No power and control voltage to heater
Check that heater has power and control voltage.
Faulty component
Check components with continuity meter. Replace,
as necessary.
Not enough heat
Faulty component
Check that ampere draw is reasonably close to that
on the heater data plate. If more than 10% short,
begin testing individual components. Replace, as
necessary.
Heat anticipator current draw too low, causing short
cycling.
Check current draw.
Heater cycling on automatic limit
Improper airflow
Check for obstructions to return air, loose or broken
fan belt, and clogged filters and/or evaporator coils.
Faulty temperature limit switch
Test, and if necessary, replace.
Open secondary protective
device
Stuck contactor
Check contactor.
Contractor chatter
Improper wiring
Check wiring.
Insufficient transformer capacity
Check transformer.
Element failure
Corroded hardware and/or loose connections
Check hardware.
