89
VAPOR-LOGIC
®
VERSION 6 INSTALLATION AND OPERATION MANUAL
Table 89-1:
Troubleshooting guide (continued)
Gas-to-steam (GTS) humidifier issues
Issue
Possible causes
Actions
Alert:
Blocked flue
• Blocked flue sensor is open
• Check venting system for obstructions .
• Check air line to flue switch for obstructions .
• Windy conditions cause downdrafts in venting system . Install
a high wind vent cap or isolate as recommended by local
codes .
Alert:
Gas valve [number]
fault
• Failed ignition module
• Miswired gas valve
• Check ignition module . Replace if necessary .
• Check gas valve wiring .
Alert:
Burner [number] fault
• No gas supply to unit
• Verify that gas service valve is on and receiving minimum
pressure to manifold per rating plate .
• Gas valve is off or there is no power to the
valve
• Check for 24 VAC from the ignition module to the gas valve .
• Check that gas valve plug is seated properly .
• Gas valve outlet pressure is too low
• Verify outlet pressure is set per rating plate .
• Blower inlet is dirty or obstructed
• Clean inlet and check for obstructions .
• Flame sensor not sensing flame
• Check flame sensor wiring .
• Check polarity at incoming power . Switch if necessary .
• Stray fiber from burner touching flame sensor . Use a
screwdriver to gently push down fibers near flame sensor .
• Flame sensor is cracked . Replace .
• Polarity reversed at power block
• Check polarity .
Alert:
Ignition module [number] fault
• Ignition sequence engaged without power to
gas valve
• Verify ignition sequence .
• Replace ignition module .
• Gas valve/ignite/sensing electrode is out of
sequence
• Verify wire connections to gas valve, ignitor, and flame
sensing rod .
Alert:
Blower [number] fault
• The blower is incorrectly wired, or the
blower failed to meet demand speed
• Check for proper blower wiring .
• Replace blower .
Alert:
No power vent airflow
• The power venter air flow switch is open
• Check for proper power vent wiring .
• Repair or replace power venter .
Alert:
Flue temperature switch
• Flue temperature is too high
• Tank is not full
• Unit automatically shuts off and cools down . The unit will
automatically restart when flue temperatures return to
normal .
Alert:
Tank temperature switch
• Flue temperature is too high
• Tank is not full
• Excessive inlet water temperature (over 90°F [32°C]) .
• Check if water supply line strainer is plugged .
• Clean scale from tank and heat exchanger .
• Check supply water pressure . Provide supply water pressure
as specified on unit .
Alert:
Flue or tank overtemp cutout
• Flue temperature is too high
• Excessive inlet water temperature (over
90°F [32°C]) .
• Unit automatically shuts off and cools down . The unit will
automatically restart when flue temperatures return to
normal .
• Tank is not full
• Check if water supply line strainer is plugged .
• Check supply water pressure . Provide supply water pressure
as specified on unit .
• Excessive scale for tank and heat
exchanger
• Clean scale from tank and heat exchanger .
Alert:
Flue sensor out of range
• Signal outside of 4-20mA
• Check P4 voltage from CS1 to ground (2-10vdc)
• Replace transmitter if no voltage output
• Check voltage on P6 from 21vdc to ground is 21vdc . If not,
re-check terminals for all field connections .
Troubleshooting guide
TROUBLESHOOTING