Qmark MWUH Series - Horizontal / Downflow Unit Heaters - Manual (Page 4)

OPERATING
INSTRUCTIONS
1. Heater must be properly installed before operation.
2. After heater is completely assembled, rotate thermostat knob
counterclockwise until control stops. This is the minimum
heat setting.
3. Turn power supply to heater “ON” at main switch panel.
4. Heater should not operate. If it operates disconnect power
and recheck wiring.
5. Rotate thermostat clockwise until it stops (maximum heat set-
ting).
6. Heater should turn on after a brief delay (see Automatic Fan
Delay below). If heater and fan do not come on, disconnect
power and check wiring.
NOTE: The first time you operate the unit, it may smoke slightly.
This is due to the residual cleaning agents used to clean the ele-
ment when the heater is manufactured. This is normal and does
not indicate a problem with the unit. This condition will stop after
the heater has been in operation for a few minutes.
7. Allow heater to continue to operate until room temperature
reaches desired comfort level. Then rotate thermostat knob
counterclockwise slowly until thermostat clicks off. (Note that
the fan delay will keep the fan running until the elements
cool.) Heater will cycle on and off to maintain room tempera-
ture.
8. It may be necessary to readjust thermostat a time or so until
exact comfort level is attained. Rotation in the clockwise
direction will increase the amount of time the heater will pro-
duce heat. Rotation in the counterclockwise direction will
reduce the amount of time the heater is on.
Automatic Fan Delay: The MWUH has an automatic fan delay.
When the thermostat calls for heat, fan action is delayed
momentarily until the heating elements warm. This prevents the
circulation of cold air. When the heater raises the temperature of
the room to the thermostat set point, the heating element is
turned off but the fan will continue to run until the heating ele-
ment cools down. This prevents exposing the unit to residual
heat, provides a higher comfort level and prolonged element life.
Automatic Thermal limit: The MWUH is equipped with a ther-
mal limit which will automatically shut off the heater in the event
of overheating. The heater will turn on when the operating tem-
perature returns to normal. Should the unit overheat and activate
the thermal limit, the cause of the overheating should be deter-
mined before further operation.
NOTE: If the unit is installed in an area where the temperature is
below 50° F, the fan may cycle on and off until the temperature
in the room rises above 50° F, this is normal and does not indi-
cate a problem with the unit. As soon as the heater warms the
air in the room above 50°, the fan will operate continually until
the thermostat has reached the room set point.
Adjusting Air Flow Direction
You can adjust the direction of air flow by:
1. Turning the unit. If the unit has been installed with a single
lag bolt, as shown in Figure 4-A, simply turn the entire unit as
needed to adjust air flow.
2. Tilting the unit. Loosen the bracket screws, tilt the heater to
the desired position, and re-tighten the bracket screws (see
Figure 4).
NOTE: To tilt the heater it must be mounted in bottom key hole
slots of mounting bracket to maintain adequate clearance and
prevent possible overheating.
3. Adjusting the louvers to the desired position.
NOTE: The louvers are designed so they can not be completely
closed. Do not attempt to defeat this feature, damage to the unit
can result.
It is important to keep this heater clean. Your heater will give you
years of service and comfort with only minimum care. To assure
efficient operation follow the simple instructions below.
User Cleaning Instructions:
1. After the heater has cooled, a vacuum cleaner with brush
attachment may be used to remove dust and lint from exterior
surfaces of the heater including the grille openings.
2. With a damp cloth, wipe dust and lint from grille and exterior
surfaces.
3. Return power to heater and check to make sure it is operat-
ing properly.
Maintenance Cleaning Instructions:
(To be performed only by Qualified Service Personnel)
At least annually, the heater should be cleaned and serviced by
a qualified service person to assure safe and efficient operation.
After completing the cleaning and servicing, the heater should
checked for proper operation.
DO NOT TAMPER WITH OR BYPASS ANY SAFETY LIMITS
INSIDE HEATER.
CAUTION - DO NOT CONTINUE TO ATTEMPT TO USE THE
HEATER IF THE THERMAL LIMIT REPEATEDLY OPERATES.
TO DO SO COULD PERMANENTLY DAMAGE THE HEATER
OR CREATE A FIRE OR SAFETY HAzARD.
ALL SERVICING BEYOND SIMPLE CLEANING THAT
REQUIRES DISASSEMBLY SHOULD BE PERFORMED BY
QUALIFIED SERVICE PERSONNEL.
TO REDUCE RISK OF FIRE AND ELECTRIC SHOCK OR
INJURY, DISCONNECT ALL POWER COMING TO HEATER
AT MAIN SERVICE PANEL AND CHECK THAT THE ELEMENT
IS COOL BEFORE SERVICING OR PERFORMING
MAINTENANCE.
4