Installation instructions S-HR series page 22
11.4 Maintenance
If it is necessary to clean the unit the following actions to
the following components must be carried out:
The air unit
Dirt which is sucked in by the air supply pipe will end up
in the bottom of the air box. This dirt can be cleaned with
a cloth with a simple (non-abrasive) cleaning agent.
Do not use an abrasive agent for cleaning,
this causes disturbing scratches in the air
box.
The burner ceramic bricks and heat exchanger
These components should only be cleaned if it is
determined that the maximum Pa is no longer obtained
as described in chapter 12.1.
The fan unit must be removed in order to be able to
inspect the heat exchanger. In this case the following
actions must be carried out:
- close the gas valve and isolate the units electrical
supply;
- turn the Control Tower forward around its left hinge
point and remove the plastic air box;
- loosen the nut of the gas pipe under the gas block;
- loosen the small crosshead screw on the red
electrical connection adaptor of the gas block;
- remove the electrical connection plug from the fan
motor;
- loosen the front crosshead screw of the black plastic
air inlet damper;
- after this turn the two clamping rods ¼ turn and
remove them by pulling them forward;
- slightly lift the fan unit and remove it towards the front
of the heat exchanger;
- the fan unit and the air inlet damper can be checked
for contamination and if necessary cleaned;
- now remove the burner ceramic bricks by slightly
lifting them upward and removing them in the same
direction as the heat exchanger fan unit;
- the burner ceramic bricks and the heat exchanger
can be cleaned by means of a soft brush;
Refitting of the components is done in reverse.
The following components require extra attention
before and after refitting:
- make sure that the gasket for the ceramic bricks is
fitted onto the heat exchanger precisely;
- make sure that the fan unit clamping rods have been
pushed backward sufficiently and that they have
again been turned ¼ turn;
- make sure that the gas connection under the gas
block is tightened;
The waste trap
In order to check the waste trap for contamination the
following actions must be carried out:
- make sure that the unit is off by isolating the units
electrical supply;
- turn the Control Tower forward around its left hinge
point;
- turn the waste trap cup to the left until it is released
from the screw thread;
Do not use pliers or wrenches for removing
the waste trap cup
Refitting is done in reverse order.
11.5 Further checks
Checking the ionisation current.
- ionisation determines if there is a flame present with
correct combustion. The measurement is done by
means of connecting a Micro ampere gauge in
series with the ionisation thread. The minimum
allowed ionisation is 2 µA. The unit will modify its load
anyway if the ionisation reaches the bottom limit of 2
µA.
Checking by means of a visual inspection.
- A visual inspection entails viewing and checking of a
number of components with regard to their
functioning.
The safety valve may not show any traces of leaks.
The waste trap should be clean.
The central heating water filter only requires
cleaning if the circulation pump is adjusted at maxi-
mum speed and the maximum
D
T is exceeded.
11.6 The frequency of maintenance
STREBEL advise to carry out an inspection to the unit
every two years and an overhaul every four years. When
doing this the circumstances of the units location must
be taken into account, From this one can determine
whether to deviate from this advice.
