14
VAPORMIST
®
DI TROUBLESHOOTING GUIDE
PROBLEM
POSSIBLE CAUSE
RECOMMENDED ACTION
Humidifier will not heat.
Control transformer
Reset control transformer circuit breaker.
Humidistat is not calling
Set humidistat to call. Inspect for faulty humidistat.
Safety controls open
Check safety controls, air flow switch, high limit humidistat, etc.
Low water cutoff
Check at board 32 and 33. Measure 0 volts for closed switch,
approximately 2.5 volt for A.C. open switch.
Humidifier will not fill.
No water pressure at valve
Check manual water supply valve for minimum 25 psi (172 kPa)
water pressure.
Malfunctioning float switch
Check to make sure that float moves freely on stem.
Plugged fill valve
Check fill valve inlet.
Humidifier does not stop
filling.
Open drain valve
Obstruction in drain valve will not allow complete closure. Clean or
replace valve.
Manual drain valve not closed
Close drain valve.
Fill valve stuck open
Check valve for foreign matter, water-logged float, broken float arm
worn valve stopper.
Reduced or no output
even though water is at
the proper level
Heater malfunctioning
Verify that proper voltage is being applied to heaters. Check heater
amp draw and compare to wiring diagram ratings.
Malfunctioning control system
Replace heater contactor if not functioning. Verify auxiliary limit
controls (humidistat, air flow proving switch, etc.) and reset, replace
or calibrate as needed.
VMOM-0600.PDF 14
11/19/2009 9:59:11 AM
