MHG Heating ProCon HT Installation And Operating Manual page 71

If any coils appear to be significantly dis-coloured, then a blockage of either scale,
magnetite, or general system debris has occurred which will have allowed excessive
overheating to have occurred within the coil.
If dis-colouration has occurred, then specialist de-scaling of the heat exchanger will be
required, however, stress cracking may have occurred, and the heat exchanger may become
porous following the de-scale works.
i) If the heat exchanger has not suffered from dis-colouration, as 'Item h' above, then a
Standard Service can be undertaken. Using a natural bristled brush ONLY, remove the worst
of the mineral/debris build up.
With the use of the dissolved
solution onto the heat exchanger surface and leave for approximately 5 minutes. This will
help to remove any stubborn mineral deposits. Finally brush the heat exchanger whilst
rinsing thoroughly with copious amounts of fresh water.
Cleaning Granules
PVC BRUSH MUST NOT BE USED TO CLEAN THE HEAT EXCHANGER.
j) Following the cleaning of the Heat Exchangers, the condensate syphon must be flushed to
ensure that all mineral deposits/debris that has been washed from the heat exchanger
surface is correctly removed. Open the syphon cleaning point cap at the base of the boiler,
with a suitable receptacle directly below to collect the syphon contents. Safely dispose of
the contents of the syphon. Replace the receptacle below the cleaning point and poor 2
litres of clean tap water into each of the heat exchangers, which will drain through the
cleaning point. Refit the cleaning point cap and poor half a litre of clean tap water into
one of the heat exchangers to ensure the syphon is re-flooded. Check the cleaning point cap
for leaks.
k) Visually check the burner surface for signs of damage and debris build-up. Remove any
debris build up with compressed air. If excessive debris build-up is identified, the burner
lance should be removed and the inner metal surface should be washed and cleaned. A
BRUSH, OF ANY KIND, MUST NOT BE USED TO CLEAN THE BURNER SURFACE. If damage has
occurred to the burner surface, the burner MUST be replaced.
l) To ensure that the rectification circuit operates correctly the resistance between the burner
and burner door must be check with a multi-meter to ensure that it is less than 1 Ohm (<1
Ohm.)
m) Clean with abrasive material and inspect the ignition electrode. Replace if necessary. Adjust
the spark gap to 4mm.
n) Check the combustion fan blades for debris build-up. Remove any debris with a soft bristle
brush or preferably compressed air. DO NOT TOUCH, OR SPIN, THE FAN BLADES WITH YOUR
FINGERS AS THIS COULD AFFECT THE BALANCING OF THE FAN BLADES.
o) Re-fit the Burners, in the reverse order of dismantling, ensure that all electrical connections
are correctly and securely connected.
p) Inspect all water joints. Any joints found to be leaking MUST be replaced. It is also advisable
when replacing water joints to also change any adjacent joints at the same time.
q) Inspect all gas joints with a suitable leak detection method. Any joints found to be leaking
MUST be replaced. It is also advisable when replacing gas joints to also change any adjacent
joints at the same time.
r) Via the tappings on the boiler connector elbow or straight a flue gas recirculation check
must be undertaken when the boiler is operating on high and low fire modes.
s) Inspect and clean the condensate neutralising tank, replenishing the neutralising granules
as required. Granules available from MHG Heating Ltd Spares Department.
t) With the use of a suitable Flue Gas Analyser, check and adjust the combustion settings, as
detailed in Section 15.2.
u) Inspect the general condition of the flue system, including the termination, repair as
necessary or advise on any remedial action as required.
v) Following the satisfactory completion of the above service procedure, the internal Routine
Service Control Timer needs to be reset. Utilising the QAA73 Room Unit/Service Tool gain
access to the Second Level Parameters, as detailed in Section 14.2, and select Parameter Line
H630 – Bit 6. using the + button, adjust the value from 0 to 1 and press the INFO button to
reset the Service Interval counter.
MHG Heating Ltd, Unit 4 Epsom Downs Metro Centre, Waterfield, Tadworth, Surrey, KT20 5LR
P:0845 6448802 F:0845 6448803 E:
© MHG Heating Ltd
ProCon Combustion Chamber Cleaning Granules
are available from MHG Heating Ltd Spares Department. A STEEL OR
info@mhgheating.co.uk
011011
, spray the
ProCon Combustion Chamber
W: www.mhgheating.co.uk
71