6.3.10 Set the thermostat to MAXIMUM.
6.3.11 Ensure that the Main Burner has now ignited.
6.3.12 Test for gas leakage at the supply, Multifunctional Control, Pilot and Main burners using a proprietary detection
fluid, and sealing any leaks found.
6.3.13 Allow the heater to operate for a minimum of 15 minutes to ensure stability.
ZZ1031/4
8
Fig. 3
Pilot Burner Assembly
6.4
MAIN BURNER PRESSURE TEST AND TEMPERATURE RISE CHECK:
6.4.1
Referring to Table 4 and Fig. 4 below, ensure that the pressure test gauge indicates correct pressure, adjusting the
supply pressure if required.
a.
At the Multifunctional control:
i.
Remove the Burner Pressure Adjuster cover.
ii.
Set the Burner Pressure Adjuster to provide a pressure test gauge indication for the correct burner
pressure as detailed in Table 4.
iii.
Refit the Burner Pressure Adjuster cover.
6.4.2
Check that the temperature rise across heater is between 45
o
C - 55
o
C, setting the fan speed accordingly by
alteration of the voltage selection at the tap changer on the control panel, (decrease voltage to decrease fan speed
thus increase temperature).
Note: Tapping 1 = 150V, Tapping 2 = 170V, Tapping 3 = 190V, Tapping 4 = 210v and Tapping 5 = 230V.
1. Operating control
2. Burner Pressure Adjuster
3. Pressure test point
4. Pilot Adjuster
Fig. 4
Multifunctional Control
ZZ1031/4
11
8.
MAINTENANCE
IMPORTANT: Ensure that the 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 6.7 inclusive.
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 lower front door.
8.2.3
Disconnect the Multifunctional Control electrical connection.
8.2.4
Disconnect the gas supply by breaking the union at the input side of the Multifunctional Control.
8.2.5
Remove the Burner Assembly fixing 3 x screws and withdraw the Burner Assembly.
8.2.6
Refit the Burner and Control Assembly in reverse order.
8.3
BURNER ARM REMOVAL AND CLEANING:
8.3.1
Remove the Burner and Control Assembly as detailed in 8.2.
8.3.2
Remove the Pilot Burner Assembly as detailed in para 8.5
8.3.3
Remove the 2 x screws and lock washers securing burner arm to Main Burner Assembly, and remove the burner.
8.3.4
Clean the burner thoroughly both inside and out with a soft brush.
DO NOT ENLARGE, DISTORT OR
DAMAGE THE BURNER HOLES
.
8.3.5
Reassembly or replacement is in reverse order.
8.4
MAIN INJECTOR REMOVAL, CLEANING AND REPLACEMENT:
8.4.1
Remove the Burner and Control Assembly as details in 8.2
8.4.2
Unscrew the main injector from the extension fitted to the housing.
8.4.3
Clean as necessary.
DO NOT ENLARGE, DISTORT OR DAMAGE THE MAIN INJECTOR HOLE.
8.4.4
If the injector is to be replaced, ensure that it is correctly marked, referring to the Data Badge for details.
8.4.5
Refit or replace injector in reverse order.
Pilot Burner
Electrode
Thermocouple
4
3
1
2
