10
8.
MAINTENANCE
IMPORTANT: Ensure gas and electricity supplies are isolated before commencing any maintenance or
replacement of components. After completion of any maintenance, always test for gas soundness and carry
out a complete functional test of the appliance in accordance with Commissioning Instructions at Sect 6.1
to 6.8 inclusive. Replace any sealing gasket or insulation that is damaged before re-commissioning, taking
care to not disperse fibrous materials.
8.1
ROUTINE MAINTENANCE:
8.1.1
Operate the appliance and check for the correct function of the burner and controls.
8.1.2
Turn OFF the gas and electrical supplies to the appliance.
8.1.3
Remove the air heater front panel.
8.1.4
Remove and check the return air filter/cleaner for cleanliness, remove and clean the Air Circulation fan as
detailed in para 8.8.
8.1.5
Remove the Burner and Controls Assembly as detailed in para 8.2. Inspect and clean the main burner and injector
as necessary. Examine the main burner for cracks, including hairline cracks, exchanging the burner as necessary.
8.1.6
Inspect and clear the pilot burner orifice.
8.1.7
Clean the heat exchanger flueways by thoroughly brushing from above and below.
8.1.8
By viewing through the Fan Aperture, and using a torch or similar, examine the heat exchanger externally for signs
of cracks or holes, particularly around welded joints.
8.1.9
Using a torch or similar, introduce a light source into the heat exchanger burner aperture and upper access port,
and again examine the heat exchanger for signs of cracks or holes, particularly around welded joints, whilst again
viewing through the Fan Aperture.
8.1.10 Refit the Air Circulation fan, Burner and Controls Assembly, and air filter/air cleaner.
8.1.11 Light the appliance and note the main burner flame profile. If the flame profile is affected when the Air
Circulation fan switches on, check for any air leaks between the air heater and the base plenum, paying particular
attention to heaters with rear draught diverters. Rectify any air leaks before continuing with this procedure.
8.1.12 Allow the air heater to operate for approximately 15 minutes to ensure stability, and with the main burner lit,
ensure that the operation of Air Circulation fan does not affect the main burner flame profile.
8.1.13 If no defects are found, fully commission the air heater in accordance with the Installation, Commissioning and
Maintenance instructions applicable to the appliance.
8.2
BURNER AND CONTROL ASSEMBLY REMOVAL:
8.2.1
Ensure that the Gas and Electrical supplies are switched OFF
8.2.2
Remove the appliance door.
8.2.3
Disconnect igniter at the piezo unit.
8.2.4
Disconnect Multifunctional control electrical connections.
8.2.5
Disconnect the gas supply by breaking the union at the input of the Multifunctional control.
8.2.6
Remove the 9 Burner assembly securing screws and withdraw the Burner and Control Assembly.
8.2.7
Refitment or replacement is in reverse order.
8.3
MAIN BURNER REMOVAL:
8.3.1
Remove the Burner and Controls assembly as detailed in 8.2.
8.3.2
Disconnect the pilot gas feed pipe from the Multifunctional control and the Pilot Assembly.
8.3.3
Disconnect the Thermocouple from the Multifunctional control.
8.3.4
Release the 4 x securing screws and withdraw the Pilot Assembly.
8.3.5
Release the 2 x hexagonal headed screws situated above the main injectors, and remove the injector shrouds.
8.3.6
Remove the 2 x main injector holders complete with injectors.
8.3.7
Release the 2 screws securing the Main Burner to the burner plate and withdraw the Main Burner.
8.3.8
Refitment or replacement is in reverse order.
8.4
MAIN INJECTOR REMOVAL:
8.4.1
Remove the Burner and Controls assembly as detailed in 8.2.
8.4.2
Release the 2 x hexagonal headed screws situated above the main injectors, and remove the injector shrouds.
8.4.3
Remove the 2 x main injector holders complete with injectors.
8.4.4
Unscrew the main injectors from the holders.
8.4.5
Refittment or replacement is in reverse order.
15
CHECK FOR 230V AT
TERMINAL 27
MAIN BURNER NOT OPERATING
IS
PILOT
LIT ?
IS TIME
CONTROL &
THERMISTA-STAT
CORRECTLY
SET ?
IS
GAS
ON ?
N
N
LIGHT
PILOT
Y
Y
SWITCH ON
230 V
N
Y
N
Y
SET CONTROLS
CORRECTLY
DISCONNECT THERMISTA-STAT
AT TERMINALS ‘7’ & ‘8’, LINK
TERMINALS ‘7’ & ‘TEST’
IS 230V
SUPPLY
ON ?
Y
RECONNECT THERMISTA-STAT
AT TERMINALS ‘7’ & ‘8’,
DISCONNECT ON CONNECTION
AT THERMISTA-STAT
DOES
FAN
RUN ?
DOES
FAN
RUN ?
Y
REPLACE
THERMISTA-STAT
N
EXTERNAL WIRING TO
THERMISTA-STAT
FAULTY
CHECK FOR 230V AT
MULTIFUNCTIONAL
CONTROL
N
Y
REPLACE
MULTIFUNCTIONAL
CONTROL
Y
CHECK WIRING TO
MULTIFUNCTIONAL
CONTROL
N
CHECK FOR 230V AT
TERMINAL 15
N
CHECK FOR 230V AT
TERMINAL 13
Y
LINK TERMINALS ‘13’
& ‘14’, IF BURNER
LIGHTS REPLACE
FAN/LIMIT CONTROL
N
CHECK FOR 230V AT
TERMINAL 29
CHECK WIRING
CONNECTIONS
Y
TURN GAS
ON
N
REPLACE
ELECTRONIC
MODULE
Y
CHECK WIRING
CONNECTIONS
Y
N
CHECK FOR 230V AT
CENTRE TERMINAL OF
SWITCH ‘S5’
N
CHECK FOR 230V AT
TIME CONTROL
TERMINAL ‘C5’
REPLACE AIR HEATER
SWITCH
Y
N
REPLACE TIME
CONTROL MECHANISM
SYSTEM E-T DEFECT DIAGNOSIS FLOW CHART
