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UHA UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL
24
SECTION 12: SERVICING
12.1 Servicing Instructions
After start-up, the heater will require maintenance to
be carried out annually. If the heater is used in a
dirty or dusty area, more frequent maintenance may
be necessary.
NOTE 1: After any maintenance or repair work,
always test fire the heater in accordance with the
start-up instructions on Page 19, Section 10 through
Page 21, Section 10.3.1 to ensure all safety systems
are in working order before leaving the heater to
operate. Minor faults may be traced by using the
troubleshooting charts on Page 27, Section 13
through Page 30, Section 13.5.
NOTE 2: Check all gas pipes and pipe joints to
ensure there are no cracks or gas leaks. Any cracks
in the pipes or pipe joints must be repaired.
NOTE 3: Inspect all suspended components and
hardware. Ensure that they are in good condition,
properly tightened, and corrosion free.
12.2 Burner Maintenance
1. Open the door and remove the burner compart-
ment cover. See Page 32, Section 14.2.
2. Clean any deposits from the main burner which
may have formed in the injectors or venturi of
the burner. See Page 32, Section 14.2.
3. Remove the ignition electrode and flame probe.
Check condition of ignition electrode and flame
probe. Clean off any deposits which may have
been formed, check condition of ceramic
insulators. Replace as necessary.
12.3 Fan/Motor Assembly Maintenance
The main fan bearings are permanently sealed and
do not need lubrication. Before cleaning, turn off gas
and electrical supply. Remove the fan and use a
small brush or duster to clean the fan blades from
each side. Replace fan when done.
12.4 Heat Exchanger Maintenance
The heat exchanger will remain clean unless a
problem has developed with combustion. Inspect the
heat exchanger. Look for signs of overheating at the
front tubes which may indicate burner over firing or
persistently low air flows.
12.5 Gas Valve Maintenance
No regular maintenance is required on this device.
To change gas control valves, See Page 31, Section
14.1.
Do not repair or disassemble gas valve.
Replace faulty gas valves with genuine
replacement parts sold and supplied by
Roberts-Gordon.
12.6 Flue Blower
The flue blower should not require maintenance.
However, if the air pressure switch is causing burner
lockout, then remove the flue blower from the vent
box by unscrewing the three screws at the mounting
plate. Remove the four screws attaching the
mounting plate to the fan inlet (See Page 35,
Section 14.6). Ensure that the fan is free to run and
that the fan wheel is clean.
12.7 Venting and Air Intake Pipe
Inspect all venting and air intake pipe. Ensure that
all seams are sealed and suspension points secure.
Repair suspension points if any part of the venting
or combustion air pipe is sagging. Check to make
sure any insulation is not missing or in poor
condition. Replace as necessary. Check all venting
and air intake components to ensure they are in
good condition, gas tight and corrosion-free.
WARNING
Cut Hazard
Turn off gas and electrical supply before maintenance.
Fan can start automatically at any time.
Failure to follow these instructions can result in severe
injury or product damage.