Water Connection; Installing Frostcontrol (Safety/Drain Valve); Routing Of Water Pipes - Truma Combi 4 Einbauanweisung

Water connection

For operating the water heater it is possible to use all pressure
pumps and submergible pumps up to 2.8 bar, also all mixing
taps with or without electrical switch.
If using immersion pumps, a non return valve (21 – not in-
cluded in delivery) must be installed between the pump and
the first branch. Observe the direction of flow when installing
the non return valve.
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28
27
25
When using pressure pumps with high switching hysteresis,
hot water may flow back via the cold water tap. We recom-
mend installing a non return valve (22 – not included with
delivery) between the outlet to the cold-water cock and
FrostControl as a return flow inhibitor. Observe the direction
of flow when installing the non return valve.
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28
27
25
For attachment to the boiler and FrostControl, you must use drink-
ing water compatible hoses that are pressure-resistant and hot
water-resistant up to 80 °C with an inside diameter of 10 mm.
For routing rigid pipes (e.g. John Guest System) Truma can
supply the elbow fittings (27 + 28), the FrostControl (24) and
a non-return valve (21 + 22) with a 12 mm inner connection
as accessories. In this case we recommend the use of John
Guest pipes, insertion sleeves and hose clamps in all cases.
When connecting to a central water supply (rural or city
mains) or if using more powerful pumps, a pressure reduc-
tion valve must always be installed which prevents pressures
above 2.8 bar from developing in the water heater.
Route water ho ses as short as possible and free of kinks.
All hose con nections must be secured with hose clamps
(also cold water hoses)! Before the pressure relief valve in
FrostControl triggers, warming of the water and its resulting
expansion may cause pressure of up to 4.5 bar to occur (also
possible with immersion pumps).
When installing a water supply into the vehicle, please ensure
that there is an adequate distance between the water hoses
and the heat source (e.g. heater, warm air duct).
Hose clips SC (part no. 40712-01) are suitable for fastening
the hoses to walls or the floor. These hose clips also make it
possible to route water hoses on the heater's warm-air distri-
bution pipes as a way to avoid the danger of frosting.
A water hose may only be fitted at a clearance of 1.5 m to the
heater on the warm air duct. The Truma hose clip SC can be
used if this distance is observed. In the case of parallel instal-
lations, e.g. openings through a wall, a spacer element should
also be attached (e.g. insulation) to prevent contact.
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21
23
24
26
23
22
24
The included elbow fittings (27 + 28) must always be
used in order to completely empty the water and prevent
the water hoses on the unit from leaking over the long-term!
Elbow fitting (28 – with aeration valve) is connected to the
upper warm water connection; the second elbow fitting (27) is
connected to the lower cold water connection.
Route all water lines so they drop down to FrostControl!
There shall be no guarantee claims for damage
caused by frost!

Installing FrostControl (safety/drain valve)

FrostControl must be installed in the immediate vicinity of the
unit in the heated room in a position that the user can easily
access. Make sure that rotary switch (30) and push button (31)
can still be operated.
When selecting a location, please ensure that the FrostControl
(24) is not installed in the vicinity of external heat sources
(e.g. power supplies) or in the immediate proximity of warm
air pipes.
Drain directly to the outside at a position protected against
splash water (apply splash guard, if necessary).
24
31
31
25
Drill a hole (18 mm diameter) in the floor of the vehicle. Attach
drain tube (24a) to drain connection, insert both through the
floor and route outside. Seal gap between drain hose and hole
with plastic body sealant from below. Fasten FrostControl with
two screws B 5.5 x 25 (included with delivery).

Routing of water pipes

Connect cold water supply (23) to FrostControl (24). Route the
water hoses without tension in order to ensure that the safety/
drain valve will work properly!
Slide elbow fitting (27) onto cold water connecting pipe and
elbow fitting with integrated ventilating valve (28) onto hot
water connecting pipe of heater as far as it will go. Pull in
opposite direction in order to make sure the elbow fittings are
securely attached.
30
23
24a
32
29
20 mm 45º
28
27
15