Gas Connection; Water Connection - Truma Combi series Einbauanweisung

The warm air system is designed individually for each vehicle
type using the modular design principle. A wide range of ac-
cessories is available for this purpose.

Gas connection

The 30 mbar operating pressure of the gas supply must
correspond to the appliance's operating pressure (see
type plate).
The ducts must be routed in such a way that the appliance is
easy to remove for service work.
The gas supply line (Ø 8 mm) must be attached to the gas
connection muff (20) with an olive screw connection (19 – in-
cluded with delivery depending on version). Carefully counter-
hold with another wrench when tightening.
The gas connection muff (20) on the appliance may not be
shortened or bent.
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Figure 13
Before connecting to the appliance, please ensure that the
gas ducts are free of dirt, shavings and the like.
The number of separation points in the gas supply line in
rooms used by persons must be limited to the technical
minimum.
The gas system must comply with the technical and admin-
istrative regulations of the respective country of use (e.g.
EN 1949 in Europe).
The national legislation and regulations (e.g. DVGW Work
Sheet G 607 for vehicles in Germany) must be observed.
EN
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Water connection

Any pressure or immersion pump up to 2.8 bar can be used to
operate the boiler, as can any mixing battery with or without
an electric switch.
If the boiler is connected to a central water supply (rural or
urban connection) or if powerful pumps are being used, a
pressure reducer must be used, which will prevent pressures
higher than 2.8 bar from occurring.
Before the pressure relief valve triggers, warming of
the water and its resulting expansion may cause pres-
sures of up to 4.5 bar to occur (also possible with immersion
pumps). The water lines for connecting to the boiler and the
safety/drain valve must be safe for drinking water, pressure-
resistant (up to 4.5 bar) and hot water-resistant up to +80 °C.
If using immersion pumps, a non-return valve (21, not includ-
ed with delivery) must be installed between the pump and the
first branch. Observe the direction of flow when installing the
non-return valve. (See figure 14 – Example of an installation
with flexible hoses Ø 10 mm).
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Figure 14
When using pressure pumps with a high switching hysteresis,
hot water can flow back via the cold water tap. We recom-
mend installing a non-return valve (22, not included with the
delivery) between the outlet to the cold water tap and safety/
drain valve as a return flow inhibitor. Observe the direction of
flow when installing the non-return valve. (See figure 15 – Ex-
ample of an installation with flexible hoses Ø 10 mm).
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Figure 15
Installation with flexible hoses (Ø 10 mm)
The elbow fittings (27 + 28) and the safety/drain valve (24)
have a connection with Ø 10 mm. All hose rubber connec-
tions must be secured with hose clamps (including the cold
water connection).
Installation with fixed duct routing (Ø 12 mm)
The elbow fittings (27 + 28) and the safety/drain valve (24)
have an inner connection of Ø 12 mm. We recommend the
use of John Guest ducts, insertion sleeves and retaining rings.
Appropriate adapters are available for connecting ducts with
different diameters (not included in scope of delivery).
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