34 of 49
Service and maintenance
Monitoring and checking
General remarks
At least once a year the appliance
should undergo the following
monitoring:
1. Check seals of water pipes and if
applicable replace.
2. Check seals of gas pipes and if
applicable replace as required.
3. Visual check of condition of all
boiler components.
4. Visual check of burner.
5. Cleaning of main heat exchanger
6. Check functional efficiency of
safety system:
i.e. Temperature protection.
7. Check functional efficiency of gas
feed safety system:
Gas and flame failure
protection (ionisation)
8. For Combi Boiler monitoring of
service water production efficiency
(checking through flow and
temperature).
9. Checking general functional
efficiency of boiler.
10. Remove any oxidization on the
electrode with the aid of an emery
cloth.
11. Check correct positioning / spark
gaps of the ignition and ionisation
electrodes as per the adjacent
picture.
12. Check the combustion fan blades
for debris build up. Remove any
debris with a soft bristle brush or
compressed air.
Cleaning of stainless steel heat
exchangers
For Cleaning the interior/dry side of the
heat exchanger coils, the burner / burner
door assembly must be removed.
For cleaning you may use water, a
cleaning agent (citric acid*) and use a
non-metal brush. Afterwards flush with
water.
Note: Never Clean the Burner itself
Cleaning of the Siphon
To gain access to the siphon, unscrew
the Condense collecting glass clockwise,
which is on the bottom left of the
underside of the boiler. Allow water to
drain out safely. Pour 2 litres of clean tap
water into the heat exchanger and allow
to drain safely through to the cleaning
point.
Refit the Condense Collecting Glass and
poor a further 2 litres of clean tap water
into the heat exchanger to ensure the
siphon is full of water.
If the appliance has not been used
for a long time, the siphon must be
filled before switching on again.
It is dangerous not to refill the siphon
with water, as in this case flue gas
can escape into the atmosphere.
Function checking
After completing the maintenance
work fill the heating circuit with a
pressure of around 1,0 bar and bleed
the appliance of air.
Also fill the service water appliance.
Set the appliance in operation. If
necessary, bleed the heating
appliance again. Check the
adjustments and correct operation
of all operator, calibration and
monitoring elements.
Check that the flue gas connection is
completely sealed with no cross
contamination to the combustion air
and is functioning correctly.
* Cleaning Granules availble from
MHS Spares Department
