COMBAT CUHA - Section 6.4 Gas Control Valves; Pilot Drop Out Test - Manual Ignition Models

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UNIT HEATER
Section 6. SERVICING INSTRUCTIONS
After commissioning, the heater will require maintenance to be carried out at least once per year to
ensure that peak performance and safety are maintained. If the heater is used in a dirty or dusty area,
then more frequent maintenance may be necessary.
WARNING
Only competent and Qualified Engineering Personnel should carry out servicing and fault
finding on this equipment.
Before any maintenance is carried out, ensure that both gas and electrical supplies are turned off as the
fan can start automatically at any time.
NOTE 1: After any maintenance work always test fire the heater in the prescribed manner to make sure
all safety systems are in working order before leaving the heater to run normally.
NOTE 2: Check all pipe joints for gas soundness using an approved method. Any leaks found must be
repaired before leaving the heater to fire normally.
NOTE 3: After routine maintenance, the commissioning procedure Section 4, should be carried out to
ensure that peak efficiency and safety is maintained.
Minor faults may be traced by use of the fault finding charts, Section 8.
6.1 Burner Maintenance
Burner maintenance is essentially the same for manual and automatic ignition heaters. Where there is
a significant difference the two types are referred to separately:
1. Remove the Burner Assembly as in 7.1.
2. Check condition of the ignition burner, ignition electrode and flame probe (for automatic), or
thermocouple (manual) as appropriate. Clean off any deposits which may have been formed on
the thermocouple or flame probe. Replace as necessary.
3. Check that the ignition gas pipe is clear of any deposits and that all joints are sound (See 7.3)
4. Check condition of ignition electrode and flame probe for erosion and damage to the ceramic
insulation (see 7.3). Replace as necessary.
5. Clean any deposits from the main burner paying particular attention to fluff etc. which may have
formed in the injectors or venturi of the burner (See 7.2).
6. Check the condition of the thermal insulation lagging at the bottom of the burner compartment
and replace if necessary. Pay particular attention to the condition of the foil face of this insulation
which must be complete and unbroken.