TM
Problem
Humidifi er will not heat
Humidifi er will not fi ll
Humidifi er will not stop
fi lling or is short cycling
Troubleshooting
Possible Cause
Blown heater fuse(s)
Control transformer not
producing 24 vac control
voltage
Safety controls open (air fl ow
switch, high-limit, etc.)
Over-temp switch
Faulty humidity sensor
Faulty immersion heater
No water pressure
Drain valve open
No power to the fi ll valve
Fill valve stuck open
Drain valve open
Probes need cleaning
Check probe wiring
Line noise or radio frequency
Recommended Action
Check and replace.
Check transformer output.
Verify voltage across terminals #9 (hot) and #10 (comm).
Verify that all safety controls are completing the safety
circuit.
The level control circuit has interference or is damaged.
Tri-probe Sensor wires should be run separate from
power wiring. Do not reset the switch until the source of
the problem is identifi ed and corrected. Consult factory
if you are unsure of the source of the problem.
Verify voltage to and from humidity sensor.
Check and verify heater voltage and amperage.
Compare to diagram or nameplate label ratings.
Check water supply.
If auto drain system is utilized, verify that the manual
drain lever on the front of the drain valve is closed.
Check for 24 vac across solenoid valve.
Check for 24 vac across solenoid valve. If no voltage,
check for dirt under valve seat.
Close drain ball valve.
If auto drain system is utilized, verify that the manual
drain lever on the front of the drain valve is closed.
Remove Tri-Probe Sensor and clean probe ends.
Grey wire to probe #1 (shortest probe)
Violet wire to probe #2 (middle probe)
Blue wire to probe #3 (longest probe)
Shielded cable may be necessary.