Operation, Maintenance, Every 1 to 4 months (depending on water quality) – Honeywell HE420A User Manual
Page 6: Caution
HE420A STEAM POWER HUMIDIFIER
68-0192—4
6
an anticipated 20°F, the control automatically maintains the
indoor relative humidity in the safe, comfortable 35% range
OPERATION
The HE420A Humidifier uses the principle that hot water
creates water vapor. As dry air and vapor mix, the relative
humidity of the air rises. The humidity control monitors the
relative humidity and activates the humidifier accordingly.
When the humidity control calls for humidity, the humidifier
underwater heater starts heating the water in the humidifier
reservoir. When the water is warm enough, the humidifier
activates a relay that turns on the furnace fan. The warm dry
air from the furnace picks up the water vapor and circulates it
through the home. The fan continues to circulate the air until
the water cools down and then turns off the fan.
Humidified air feels warmer and more comfortable so you may
be able to lower the thermostat heating setpoint and save
money on heating fuel bills giving you a more comfortable
environment that is also energy efficient.
MAINTENANCE
A regular maintenance program prolongs the life of the
humidifier and provides a more comfortable environment.
Frequency of cleanings depends on water conditions. Either
hard or soft water can be used in the humidifier, but hard water
mineral deposits are more difficult to clean.
CAUTION
Voltage Hazard.
Can cause electrical shock and equipment damage.
Disconnect power supply before installing or servicing.
IMPORTANT
Never oil any part of the humidifier.
Every 1 to 4 Months
(Depending on Water Quality)
Use the following procedure and refer to Fig. 7 to clean the
humidifier:
1. Unplug the humidifier and fan control.
2. Disconnect the humidity control wires from the external
screw terminals on the humidifier.
3. Turn off the water supply.
Fig. 7. Location of humidifier parts.
4. Disconnect water feed tubing at the float valve.
5. Disconnect the overflow at the humidifier.
IMPORTANT
Allow water to cool before continuing.
6. Press and release the MANUAL button on the Automatic
Flushing Timer.
— Wait 10-30 seconds* until the flushing noise stops,
indicating that the flushing cycle is complete.
*The number of seconds will vary depending upon
how the unit is programmed. (See “Reprogramming
Instructions” in the Auto Flushing Timer Installation
Instructions)
— Repeat Steps A and B until the humidifier is drained.
7. Remove the humidifier from the mounting.
8. Use running tap water to flush loose minerals from the
reservoir.
9. Carefully rub off minerals from the float, heater, reservoir
walls, and safety float switch.
NOTE: Steel wool or other scouring pads can be used on the
reservoir walls and other parts.
10. Inspect the valve arm and float for mineral buildup and
deterioration.
IMPORTANT
• Replace the float valve when it shows any signs
of deterioration.
• The float valve should shut off the water at
2-3/8 in. (60 mm).
Table 2. Automatic Humidity Control Settings.
Outside Temperature
Recommended RH
+40°F
45%
+30°F
40%
+20°F
35%
+10°F
30%
0°F
25%
-10°F
20%
-20°F
15%
Table 3. Recommended Frost Factor Settings.
Humidity Level
Recommended Adjustment
Insufficient
humidity
Increase the frost factor dial by one setting.
Condensation on
windows
Decrease the frost factor dial by one setting.
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