3.2
Nike Mini 28 water circuit diagram.
Key:
1 - Domestic circuit flow switch
2 - Flow limiter
3 - System filler cock
4 - Gas valve
5 - Burner
6 - Primary exchanger
7 - Fume hood
8 - Fume thermostat
9 - Delivery sensor
10 - Safety thermostat
11 - System expansion tank
12 - Air valve
13 - Boiler circulating pump
14 - Domestic circuit exchanger
15 - 3-way valve (motor-operated)
16 - Automatic by-pass
17 - System drain cock
18 - 3 bar safety valve
G - Gas supply
AC - Domestic hot water outlet
AF - Domestic cold water inlet
R - System return
M - System delivery
3.3
Troubleshooting.
N.B.: Maintenance must be carried out by a qualified technician (e.g. Im-
mergas Technical Assistance Service).
- Smell of gas. Caused by leakage from gas circuit pipelines. Check sound-
ness of gas intake circuit.
- Irregular combustion (red or yellow flame). This occurs when the burner
is dirty or the boiler lamellar pack is clogged. Clean the burner or the
lamellar pack.
- Frequent tripping of the over temperature thermostat. This may be caused
by lack of water in the boiler, insufficient water circulation in the circuit or
a blocked circulator. Check via the pressure gauge that values are within
admissible limits. Check that radiator valves are not all closed and that
the circulation pump is working correctly.
- The boiler produces condensation. This can be due to obstruction of the
flue or by flues of height and section incompatible with the boiler. It can
likewise be due to operation at an excessively low boiler temperature. In
this case operate the boiler at a higher temperature.
- Frequent cutting in of the flue safety thermostat. This can be due to
obstructions in the flue. Check the flue. The flue may be blocked or of
incompatible height or section. Ventilation may be insufficient (see point
- room ventilation).
- Presence of air in the system. Check opening of the special air valve cap
(see fig. on page 89). Make sure that system pressure and pre-charge of
the expansion vessel are within the set limits; the pre-charge value for
the expansion vessel must be 1.0 bar, and system pressure between 1 and
1.2 bar
- Ignition block and flue block, see page 91 and page 85 (electrical con-
nection).
- Low water delivery: if, due to scale (calcium and magnesium salts), a
decrease in performance is noted during hot water production, it is
advisable to have chemical descaling carried out by qualified personnel
(e.g. Immergas Technical Assistance Service). Chemical descaling must
be carried out on the domestic hot water side of the domestic circuit
exchanger, in accordance with the required technical procedures. A non-
corrosive descaling product must be used in order to preserve exchanger
integrity and efficiency. Cleaning must be done without using mechanical
tools that can damage the exchanger.
3.4
Converting the boiler to other types of gas.
If the boiler is to be converted for use with a gas type other than that speci-
fied on the dataplate the relative conversion kit must be ordered for quick
and easy conversion.
Conversion of the boiler must be performed by a skilled technician (e.g.
Immergas Technical Services Centre).
To convert to another type of gas the following operations are required:
- disconnect the electrical power supply to the boiler;
- replace the main burner injectors, making sure to insert the special seal
rings supplied in the kit, between the gas manifold and the injectors;
- switch on the power supply to the appliance;
- on the boiler keypad, select the gas type parameter (P1) and then select
(nG) for Methane or (LG) for LPG;
select the gas type parameter (P2) for gas G110;
- adjust boiler rated heat output;
- adjust boiler minimum heat output;
- adjust (if necessary) boiler minimum heat output in heating phase;
- adjust (if necessary) max. boiler heating power for heating;
- seal the gas flow rate devices (if adjusted);
- after completing conversion, apply the sticker, present in the conversion
kit, near the dataplate. Using an indelible marker pen, cancel the data
relative to the old type of gas.
These adjustments must be made with reference to the type of gas used,
following that given in the table on page 97.
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