6.4
MAIN BURNER PRESSURE TEST:
6.4.1
Referring to Table 4 ensure that the pressure test gauge indicates the correct burner pressure, a low pressure
indicates a regulator fault or low cylinder pressure.
6.5
EXTINGUISHING OF BURNERS:
6.5.1
On the Multifunctional Control, rotate the OPERATING CONTROL clockwise to the ‘
z
’ position and ensure that
the OPERATING CONTROL fully resets, and both the Pilot and Main Burners are extinguished.
6.5.2
On the Multifunctional Control, remove the pressure test gauge and refit the Inlet Pressure test point cover, and
check for gas soundness.
6.6
TEMPERATURE RISE CHECKS:
6.6.1
Ignite the Pilot and Main Burners and allow 15 minutes for stability before continuing.
6.6.2
With the Main Burner operating continuously, check that the temperature rise across heater is between 45
o
C -
55
o
C, adjusting the fan speed at the control panel voltage selector, (decrease voltage selection to decrease fan
speed).
Note: Tapping 1 = 210V, tapping 2 = 175V, tapping 3 = 150V, tapping 4 = 120V and tapping 5 = 100V.
9
12
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.
8.2
BURNER AND CONTROL ASSEMBLY REMOVAL:
8.2.1
Ensure that the Gas and Electrical supplies are switched OFF
8.2.2
Remove the appliance louvre door.
8.2.3
Disconnect the igniter at the Piezo unit.
8.2.4
Disconnect the Multifunctional Control electrical connections.
8.2.5
Disconnect the gas supply by breaking the union at the input side of the Multifunctional Control, and water
heater union (if applicable).
8.2.6
Whilst supporting the Burner and Control Assembly, remove 3 x Burner Assembly fixing screws and withdraw the
Burner and Control Assembly
8.2.7
Refit the Burner and Control Assembly in reverse order.
8.3
BURNER AND CONTROL ASSEMBLY CLEANING:
8.3.1
Remove the Burner and Controls Assembly as detailed in 8.2.
8.3.2
Disconnect the Pilot Feed Pipe and Thermocouple from the Multifunctional Control.
8.3.3
Release the single screw, nut and washer securing the Pilot Assembly to the Burner and Controls Assembly, and
remove the Pilot Assembly.
8.3.4
Release the 2 screws, nuts and washers securing the Main Burner to the mounting bracket, and remove the Main
Burner.
8.3.5
Clean burner thoroughly both inside and out with a soft brush.
DO NOT ENLARGE, DISTORT OR DAMAGE
BURNER HOLES
.
8.3.6
Reassemble in reverse order.
8.4
PILOT BURNER, THERMOCOUPLE AND ELECTRODE, REMOVAL AND REPLACEMENT:
8.4.1
Remove the Burner and Controls Assembly as detailed in 8.2
8.4.2
Disconnect the Igniter lead from the Electrode.
8.4.3
Disconnect the Thermocouple from the Multifunctional Control, taking care to avoid damage to the thermocouple
capillary.
8.4.4
Release the Pilot Feed Pipe from the Multifunctional Control.
8.4.5
Release the single screw, nut and washer securing the Pilot Assembly to the Burner and Controls Assembly, and
remove the Pilot Assembly.
8.4.6
Release the Thermocouple securing nut from the Pilot Burner Assembly and withdraw the Thermocouple, taking
care to avoid damage to the Thermocouple capillary.
8.4.7
Release the Electrode securing nut from the Pilot Burner Assembly and withdraw the Electrode.
8.4.8
Release the Pilot Feed Pipe securing nut from the Pilot Burner Assembly and withdraw the Pilot Feed Pipe and
Pilot Injector from the Pilot Burner assembly, and disconnect the Pilot Injector from Pilot Feed Pipe hook.
8.4.9
Release the 2 screws securing the Pilot Burner Bracket to the Pilot Mounting bracket, and remove the Pilot
Burner Bracket.
8.4.10 Refitting or replacement is in reverse order.
NOTE: When refitting or replacing the Thermocouple, tighten only to FINGER TIGHT + 1 FLAT.
1. Operating control
2. Inlet Pressure test point
3. Outlet Pressure test point
4. Burner Pressure adjuster
Fig. 4
MULTIFUNCTIONAL CONTROL
6.7
AUTOMATIC CONTROLS CHECK
6.7.1
Set the TIME CONTROL to
‘ON’.
6.7.2
Set the room thermostat slowly clockwise until the Main Burner ignites.
6.7.3
Ensure that the fan starts to operate after a short period (approx. 1-2 minutes).
6.7.4
When the temperature reaches the control setting, ensure that the Main Burner extinguishes followed by the fan
switching off after a short period.
6.7.5
When the temperature falls below the control setting, ensure that the Main Burner re-ignites followed by fan
operation.
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.
3
2
1
4
.5
EXTINGUISHING OF PILOT AND MAIN BURNERS:
6.5.1
On the Multifunctional Control, rotate the OPERATING CONTROL clockwise to the ‘
O
’ position and ensure that
the OPERATING CONTROL fully resets, and both Pilot and Main Burners are extinguished.
6.5.2
On the Multifunctional Control, remove the pressure test gauge and secure the Pressure test point screw.
6.6
AUTOMATIC CONTROLS CHECK
6.6.1
Ignite the Pilot burner.
6.6.2
Set the TIME CONTROL to ‘
ON
’.
6.6.3
Set the Room Thermostat slowly clockwise until the Main Burner ignites.
6.6.4
Ensure that the fan starts to operate after a short period.
6.6.5
When the temperature reaches the control setting, check that the Main Burner extinguishes followed by the fan
switching off after a short period.
6.6.6
When the temperature falls below the control setting, ensure that the Main Burner re-ignites followed by fan
operation.
9
