User`s manual

INSTALLERUSERTECHNICIAN
2121
3.2 Zeus Maior hydraulic diagram.
Key:
1 - Gas valve
2 - Stainless-steel coil for boiler
3 - Magnesium anode
4 - Boiler
5 - Circulating pump
6 - Main burner
7 - Combustion chamber
8 - Primary heat exchanger
9 - Fumes extraction hood
10 - Flue extraction fan
11 - Fan safety pressure switch
12 - Sealed chamber
13 - Heating NTC limit and regulation sensor
14 - Automatic air valve
15 - Expansion tank
16 - Overtemperature safety thermostat
17 - Pump pressure microswitch
18 - Pump pressure switch
19 - System drain cock
20 - Motor-driven 3-way valve
21 - 3 bar safety valve
22 - System filler cock
23 - Domestic circuit NTC sensor
24 - 8-bar safety valve
25 - Check valve
26 - Boiler drain valve
R - System return
M - System delivery
G - Gas supply
U - Hot domestic water outlet
E - Domestic water inlet
3.3 Troubleshooting.
N.B.: maintenance must be performed by qualified
personnel (e.g. Immergas Technical Service Centre).
- Smell of gas. Caused by leakage from gas circuit
pipelines. Check sealing efficiency of gas intake
circuit.
- The fan works but the discharge of ignition on the
burner ramp is not activated. The fan may start but
the safety air pressure switch does not change the
contact. In the case check the following:
1) that the intake-exhaust duct is not too long (over
admissible length).
2) that the intake-exhaust duct is not partially
blocked (on either the exhaust or intake side).
3) that the diaphragm on the flue exhaust outlet is
commensurate with the length of the intake/
exhaust ducting.
4) that the sealed chamber is perfectly sealed.
5) that the fan power supply voltage is minimum
196 V.
- Irregular combustion (red or yellow flame). This
may be caused by a dirty burner, blocked reed
valve, or incorrect installation of the intake-exhaust
terminal. Clean the specified components and
ensure correct installation of the terminal.
- Frequent activation of the temperature overload
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 circulating pump is working correctly.
- Presence of air in the system. Check opening of
the cap on the special air valve (see fig. page 17).
Ensure 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 0.8
bar, and system pressure between 1 and 1.2 bar.
- Ignition block; see pages 19 and 4 (electrical
connection).
- Boiler NTC sensor faulty. The boiler does not have
to be emptied when replacing the NTC sensor
because the sensor is not in direct contact with the
domestic hot water present inside the boiler.