HAMWORTHY HEATING LTD
29
Wessex ModuMax
mk3
Boilers
500001308/C
10 SERVICING
A competent person registered for working on non
domestic gas appliances should check and ensure that
the flue, its support and terminal, the ventilation to the
boiler house, safety valve, drain, water filter if fitted,
pressure gauge, etc.; are in a serviceable and working
condition and still comply with the relevant standards
and codes of practice
-
see
Section 4.
10.1 Regular servicing is recommended
, preferably
by a Hamworthy appointed person, and at least
annually, to ensure trouble free operation.
For Wessex ModuMax, Hamworthy would recommend
an additional 6 monthly examination following
commissioning, acknowledging site conditions and
running hours.
Although cleaning of flue ways may not be necessary
on a yearly basis, it is important that all controls and
safety features are checked for correct operation.
Note:
-
Measuring flue gas CO
2
and gas temperatures
will give an indication of the state of the boiler flue ways
and waterways. Results should be compared with
previously measured values to establish possible loss of
efficiency.
Should remedial work be carried out on a module, then
the non
-
firing module must be electrically isolated so as
to prevent accidental operation in the event that the
installation is required for ongoing heating requirements.
10.2 Annual Service
The procedure detailed relates to a single module and
MUST
be carried out on ALL individual modules which
constitute a unit. Before servicing the boiler, the
following procedure must be carried out :
-
WARNING: Isolate all electrical supplies and turn off
the gas service valve.
1)
Remove the front casing door by unscrewing the
centre fixing.
2)
Disconnect the H.S.I. and flame probe connectors
from the respective probes. Remove the erath lead from
the flame probe.
3)
Disconnect the fan power supply and control leads
from the fan taking care with the latch on each
connector.
4)
Check that the gas service valve is closed, then undo
the lower connection union on the flexible hose (at gas
service valve connection).
5)
Carefully remove the electrical plug from the gas
valve and remove the Low Gas Pressure Switch.
6)
Remove the air inlet filter cassette. Refer to section
11.15
7)
Remove the 2 M8 burner retaining nuts and carefully
withdraw the complete burner/ fan assembly from the
heat exchanger. Separate the burner fabrication from
the fan, venturi and gas control valve .
8)
Remove and inspect H.S.I. and flame probe, ensure
they are free from debris or deposits. Test resistance
value of H.S.I. & if above 200 ohms (cold), replace with
a lower resistance unit. Check respective positions –
See Figure 10.2.
Note:
-
The H.S.I. element is very fragile.
9)
Check the burner and clean using a soft brush if
required (if possible use a vacuum cleaner to remove
the dust from inside the burner tube). After cleaning the
inside, the burner tube can be washed using clean
water. Tap the burner flange firmly downwards on a
block of wood to dislodge any residual debris from
inside the burner tube. A damaged or cracked burner
should be replaced.
Note:
-
Do not use a wire brush to clean the burner.
10)
Check and clean the filter medium by washing in
warm soapy water
. DO NOT OPERATE THE BOILER
WITH THE FILTER REMOVED!
11)
Separate the gas valve from the venturi & ensure
venturi mouth and gas feed tube are clean and free of
obstruction.
12)
Inspect the fan scroll and impellor, clean and check
for damage.
13)
Inspect the non return valve in the burner inlet duct
for smooth operation. If venturi is removed it must be
put back in exactly the same position.
14)
Separate the inlet flange and elbow fitting from the
gas control valve by removing the 4 M5 socket cap
head screws. Check that the mesh inlet filter in the gas
valve is clear of debris, remove any foreign objects
caught in the filter.
Re
-
assemble in reverse order taking care to inspect and
if necessary, replace any o
-
rings, gaskets or seals.
Refer to
Section 8.4 onwards, Commissioning and
Testing
, and test all gas joints broken or disturbed for
soundness before firing.
Carry out a combustion check by testing the flue gas
CO
2
and CO levels as detailed from
Section 8.4.
10.3 Four Year Service
Repeat the annual service as previously described but
do not refit any components to the heat exchanger.
10.3.1
To clean the heat exchanger, the use of a high
pressure water hose (40
-
80 psi) is recommended.
However provision must be made for the drainage of
water used in this process. At the rear of the boiler
module remove the condensate drain trap assembly
