Large Unit Heater
21
Operating Instructions and Owner’s Manual
MAINTENANCE
CAUTION: Turn off gas and electrical power to unit before
performing any maintenance or service operations on this
unit. Remember to follow lighting instructions when putting
unit back into operation after service or maintenance.
If any of the original wire as supplied with the appliance
must be replaced, it must be replaced with wiring material
having a temperature rating of at least 105°C.
Do not use this appliance if any part has been under water.
Immediately call a qualified service technician to inspect the
appliance and replace any gas control which has been under
water.
•
Check gas tightness of the safety shut off valves on at least an
annual basis.
•
To check gas tightness of the safety shut off valves, turn off the
manual valve upstream of the appliance combination control.
Remove the hex head plug on the inlet side of the combination
control and connect a manometer to that tapping.
•
Turn the manual valve ON to apply pressure to the combination
control. Note the pressure reading on the manometer, then turn
the valve off. Any loss of pressure indicates a leak. If a leak is
detected, use a soap solution to check all threaded connections.
If no leak is found, combination control is faulty and must be
replaced before putting appliance back in service.
Should maintenance be required, perform the following inspection and
service routine:
BURNERS
• Periodically examine burner flames for proper appearance during the
heating season.
• Before each heating season examine the burners for any deposits or
blockage that may have occurred.
Clean burners as follows:
1. Turn off both electrical and gas supplies to unit.
2. Disconnect gas supply piping, high tension and sensor leads.
Remove gas manifold. Remove burner tray.
3. Clean burners as necessary. Make sure that burner heads line up
properly to ensure flame crossover. Check spark gap on electrode
and adjust if required. The gap should be between 0.110 inch and
0.140 inch (2.79mm to 3.56mm). The gap may be checked with
appropriately sized twist drills or feeler gauges.
4. Reinstall burner tray, gas manifold, high tension and sensor leads.
Reconnect gas supply piping.
5. Restore electrical power and gas supply. Follow lighting instructions
to light unit. Check burner flame.
FLUE PASSAGEWAY AND FLUE BOX
The flue passages and flue box should be inspected and cleaned
prior to each heating season. The sequence of operation should be as
follows:
1. Turn off both electrical and gas supply to unit.
2. Disconnect combustion air blower wiring.
3. Remove screws securing flue box to unit. Remove flue box. If
necessary, remove blower assembly from flue box. Clean flue box
with wire brush.
4. Remove turbulator retention bracket and turbulators. Clean
turbulators with wire brush.
5. Remove burners as described in section “BURNERS” section.
6. Clean tubes with a wire brush.
7. Reassemble unit. The combustion air and flue box gaskets should
also be replaced during reassembly.
8. Restore electrical power and gas supply. Follow lighting instructions
to light unit. Check operation of unit.
COMBUSTION AIR BLOWER
Under normal operating conditions, the combustion air blower should
be checked and cleaned prior to the heating season with the power
supply disconnected. Use a small brush to clean blower wheel.
ELECTRICAL
1. Check all wiring for loose connections.
2. Check for correct voltage at unit (unit operating).
3. Check amperage draw.
FLUE AND CHIMNEY
Check all vent and vent connector joints for tightness. Ensure that
connections are sealed and that there are no blockages.
OTHER CHECKS
1. Inspect the area near the unit to be sure that there is no
combustible material located within the minimum clearance
requirements listed in this manual. Under no circumstances should
combustible material be located within the clearances specified
in this manual. Failure to provide proper clearance could result in
personal injury or equipment damage from fire.
2. Complete the appropriate unit startup procedure as given in the
Operation section of this Manual (see lighting instructions on the
unit rating plate.)
•
Check the burner adjustment.
•
Also check all gas control valves and pipe connections for leaks.
3. Check the operation of the automatic gas valve by lowering the
setting of the thermostat, stopping the operation of the gas unit
heater. The gas valve should close tightly, completely extinguishing
the flame on the burner.
4. If combustion air is room supplied, ensure that a 12 inch clearance is
maintained all around the inlet openings.
5. Check and test functions of all safety devices supplied with the
heater (see UNIT START-UP and UNIT WORKING SEQUENCE
sections).
