3
Water connection
Any pressure or immersion pump up to 2.8 bar can be used to
operate the boiler. Any mixing battery with or without an elec-
tric switch can also be used.
Fig. A
If using immersion pumps, a non-return valve (3, not included
in scope of delivery) must be installed between the pump and
the first branch (arrow indicates flow direction).
Fig. B
When pressure pumps with a large switching hysteresis are
being used, hot water may flow back via the cold water valve.
We recommend installing a non-return valve (4, not included
in scope of delivery) between the outlet to the hot water tap
and the drain valve as a return flow inhibitor.
Hoses with an inner diameter of 10 mm that are pressure-re-
sistant (up to 3.5 bar) and hot water-resistant must be used
for connecting to the boiler and the safety/drain valve.
For rigid pipe installations (e.g. John Guest System) Truma
can supply the water connections (5 + 6), the safety/drain
valve (7) and a non-return valve (3 + 4) with a 12 mm diam-
eter inner connection as accessories.
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.
Water hoses must be as short as possible and free of
kinks. All hose rubber connections must be secured
with hose clamps (including the cold water connection)!
Before the pressure relief valve triggers, warming of the wa-
ter and its resulting expansion may cause pressure 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 drinking water safe, pressure resistant (up to
4.5 bar) and hot water resistant up to +80 °C.
We recommend the use of hose clips (part no. 40712-01)
to attach the hoses to walls or the floor. If a gas heater
has been installed, the water hoses can be routed on the
warm air ducts using the hose clips to protect them from frost.
Figure 1
In order to ensure that all of the water in the boiler is
drained, the provided elbow fitting with aeration valve (5)
must always be used at the hot water connection!
Route all water lines so they slope downwards to the
safety/drain valve. No claims may be made under the
warranty for damage caused by frost!
Installing the safety/drain valve
Figs. A + B
Fit safety/drain valve (7) in an easily accessible location in the
vicinity of the boiler. Drill hole with diameter of 18 mm and in-
sert the drainage socket with hose (8). Secure the safety/drain
valve in place with 2 screws. Water removal can take place
directly to the outside in a splash-protected location (fit splash
guards if necessary).
Water line routing
1. Figs. A + B
Connect the cold water supply (9) to the safety/drain valve (7).
The direction of flow is irrelevant.
2. Attach elbow fitting (5) with integrated aeration valve (15)
to hot water connecting pipe (top pipe) as far as it will go. Pull
in opposite direction to check that the elbow fitting is securely
attached.
Attach elbow fitting without aeration valve (6) to cold wa-
ter connection pipe (bottom pipe) as far as it will go. Pull in
opposite direction to check that the elbow fitting is securely
attached.
Slide venting hose with outer diameter of 11 mm (14) onto
hose nozzle of aeration valve (15) and route to the outside.
Radius of arc must not be less than 40 mm.
45º
20 mm
15
6
5
14
Fig. 2
Flexible hose installation
45º
20 mm
15
6
5
14
Ø 12 mm
JG
Fig. 3
Rigid pipe installation
(e.g. John Guest System)
Cut off the venting hose about 20 mm below the vehicle floor
at a 45° angle relative to the direction of travel.
3. Figs. A + B
Manufacture a hose connection (16) for the cold water supply
between safety/drain valve (7) and elbow fitting (6 – lower
pipe) at the boiler.
4. Route hot water supply line (17) from elbow fitting with
built-in aeration valve (5 – upper pipe) to hot water consump-
tion points.
