FM90 Users Manual - Field Control Central System

FM90 - Field Control® Fresh Mist Central System Humidifier

Freshmist 90
Owners Manual
Service Hints

Service Hints

Frequently what seems to be a major problem can be solved very easily. Listed below are the common concerns with any humidifier. Check the simple things first. Remove the front panel and see if there is a crusty, white lime buildup on the media pad. The lime buildup won’t hurt the humidifier, but will reduce its output. Low output might just mean your humidifier needs cleaning. While you’re checking for lime buildup, look to see if the media wheel is turning. If not, check the power supply.

CONDITION WHAT TO CHECK WHAT TO DO

Too little Humidity
Does humidifier need cleaning.

Clean humidifier and clean or replace media pad.

Is media wheel rotating?

a. Clean or replace media pad.
b. Check to see if transformer is properly plugged in.
c. Inspect main fuse or circuit breaker.
d. Check to see if media motor is rotating.
e. Humidistat setting too low, turn knob clockwise to increase humidity.

Humidistat setting.

Set for proper outdoor temperature - lowest 24 hour temperature.

Water to unit.

Turn on saddle valve and check for possible obstruction in water line. is water supply connected?

Excessive air loss in house.

Close fireplace damper, seal around doors and windows.

Is water level correct?

Adjust float.

Is damper open?

Slide damper out for winter operation.

Too much Humidity
Humidistat setting.

Turn knob counterclockwise to decrease humidity.

Other humidification sources.

May be a temporary condition caused by moisture from laundering, bathing, cooking, etc.

Humidifier Overflows
Is humidifier level?

Level unit.

Float valve.

Service as shown in Fig. 24.

Air flow too high.

Adjust damper.

Humidifier Making Noise
Mounting or plenum.

Tighten all fasteners.

Water pressure.

A slight sound is normal as water enters humidifier.

Media Wheel.

Check clearance of media wheel in reservoir.

Humidifier Motor Comes On When Furnace Isn't Running This is a normal condition

If heating season is over.

Turn knob on humidistat to minimum setting.

If heating season is just starting.

This is a normal condition since humidistat is controlling humidifier.

<- Maintenance
Repair parts ->

CONDITION	WHAT TO CHECK	WHAT TO DO
Too little Humidity	Does humidifier need cleaning.	Clean humidifier and clean or replace media pad.
	Is media wheel rotating?	a. Clean or replace media pad. b. Check to see if transformer is properly plugged in. c. Inspect main fuse or circuit breaker. d. Check to see if media motor is rotating. e. Humidistat setting too low, turn knob clockwise to increase humidity.
	Humidistat setting.	Set for proper outdoor temperature - lowest 24 hour temperature.
	Water to unit.	Turn on saddle valve and check for possible obstruction in water line. is water supply connected?
	Excessive air loss in house.	Close fireplace damper, seal around doors and windows.
	Is water level correct?	Adjust float.
	Is damper open?	Slide damper out for winter operation.
Too much Humidity	Humidistat setting.	Turn knob counterclockwise to decrease humidity.
Too much Humidity	Other humidification sources.	May be a temporary condition caused by moisture from laundering, bathing, cooking, etc.
Humidifier Overflows	Is humidifier level?	Level unit.
	Float valve.	Service as shown in Fig. 24.
	Air flow too high.	Adjust damper.
Humidifier Making Noise	Mounting or plenum.	Tighten all fasteners.
	Water pressure.	A slight sound is normal as water enters humidifier.
	Media Wheel.	Check clearance of media wheel in reservoir.
Humidifier Motor Comes On When Furnace Isn't Running	This is a normal condition
	If heating season is over.	Turn knob on humidistat to minimum setting.
	If heating season is just starting.	This is a normal condition since humidistat is controlling humidifier.