EWHB Series Industrial / Commercial Electric Unit Heater /Maintenance Instructions, Page 1 of 1
23-2180-83-5REZ
MAINTENANCE INSTRUCTIONS
ELECTRIC SHOCK HAZARD
Potentially lethal voltages are present. Be sure to lock the branch circuit disconnect switch in the
OFF position and tag the circuit “Out for Maintenance” before working on this equipment.
RISK OF INJURY / BURN
Do not attempt to service or clean heater while unit is operating as there is a hazard from electric
shock, injury from operating fan blade and burns from hot heating elements.
Maintenance and repair must be performed by qualified service personnel only.
Electrical:
1
. Inspect all terminal connections, contactors and
conductor insulation for damage, looseness, fraying,
etc., as applicable. Tighten any loose terminals and
replace or repair wire that has damaged or
deteriorated insulation. Replace any contactor that
has contacts that are badly pitted, welded together,
or burned.
2. If reduced heat output is suspected, perform the
mechanical checks. If low heat output is still suspected
after completing the mechanical checks, verify the
condition of the heating elements by visual inspection
and by using an amperage meter to check the current
draw of each input line. Adjust the room thermostat
to its highest temperature to energize heater. All
input lines should draw approximately equal current
which should agree with the nameplate rating. If they
do not, one or more of the heating elements could be
burned out and should be replaced.
3. For heaters supplied with the optional manual reset
limit control, the electrical enclosure cover must be
opened to gain access to the reset button. See below
to locate the reset button:
Mechanical:
1. Before cleaning or servicing, ensure power has been
turned off at the service panel and the heating
elements are cool.
2. Annually check the tightness of all visible bolts and
nuts, in particular the support structure bolts and
nuts.
3. Periodically, check the motor, fan, discharge
openings, intake openings, heating elements and
control compartment for cleanliness. If necessary,
clean by using a vacuum or compressed air. Be careful
not to bend or distort the fan blade propeller.
4. Check fan motor for smooth running operation. Any
unusual noise or vibration must be investigated and
rectified.
5. The electric motors are permanently lubricated and
thermally protected. Check for smooth and quiet
operation at all inspections. Replace motor if
excessive bearing play is detected.
6. The heater may be washed down with water. Do not
use high pressure cleaning systems.
