1.1 Description
The
WST
and
WUT
temperature regulating fit-
tings and the
WSM
and
WUM
two-tap mixer
fittings are intended for operation of open
(non-pressurised) under-sink water heaters.
The pivoting outlet pipes (
1
) are equipped
with a special jet regulator.
1.2 Operation
Temperature regulating fittings
WST A
and
WUT B
» Temperature selection with left-hand tem-
perature regulating tap (
2.1
)
» Taps with right-hand tap valve (
3.1
).
Two-tap fitting
WSM A
and
WUM B
» Hot water taps with left-hand tap valve (
2.2
)
» Cold water taps with right-hand tap valve
(
3.2
)
» Mixed water taps with left-hand and right-
hand tap valve (
2.2
and
3.2
); temperature is
mixed.
1.3 Safety instructions
As the heater warms up, so the water
volume increases. In the process, the
expansion water drips through the outlet of
the fitting. This is a necessary and normal
process.
With Stiebel Eltron SNU 5 SL water heaters
with “anti-drip” function, the expansion wa-
ter is retained in the heater.
Limescale formation can block the
outlet and so put the heater under
pressure. Never block off the fitting outlet,
and do not use any perlators or air bubblers,
flow limiters, or hoses with jet regulators,
since otherwise the heater will be damaged.
1.4 Care and maintenance
A damp cloth is sufficient to clean the water
heater. Do not use any solvents or abrasive
cleaning products.
A jet regulator in the pivoting outlet pipe (
1
)
which is blocked with limescale must be des-
caled. To do this, remove the regulator from
the screw mounting.
If necessary, the jet regulator is to be replaced
with an original Stiebel Eltron jet regulator,
spare part No. 27 99 32.
1.5 Operating and installation in-
structions
Keep these instructions in a safe
place. In the event of a change of
ownership, hand them over to the new
owner, and, in the event of any maintenance
or repair work, give them to the qualified
installer for consultation.
1. Operating instructions
for the user and qualified installer
Installation and connection must be carried
out by a qualified installer, following these
installation instructions.
First remove the packing from the fitting
and accessories at the place of installation,
making sure the packing enclosures are not
thrown away. When unpacking, also check
that no accessories are left behind in the
packing material.
2.1 Components
A
and
B
1
Pivoting outlet pipe with special jet regu-
lator
2.1
Temperature adjustment tap
2.2
Hot water tap valve
3.1
Tap valve
3.2
Cold water tap valve
4
Fitting body
5
Sealing with chain retaining eye
6
Counter-screw connection with clamping
sleeve (SW 13)
7.1
Cold water inlet pipe – copper
7.2
Cold water inlet – hose
8.1
Cold water to heater – copper
8.2
Cold water to heater – hose
9.1
Hot water from heater – copper
9.2
Hot water from heater – hose
10
Choke
11
Plastic shaped component for basin instal-
lation
2.2 Description of the fitting
The
WST
and
WUT
temperature regulating fit-
tings and the
WSM
and
WUM
two-tap mixer
fittings are intended for operation of open
(non-pressurised) under-sink water heaters.
A special jet regulator is installed in the fit-
ting outlet.
A
WST
and
WSM
→
Basin
B
WUT
and
WUM
→
Kitchen sink
2. Installation instructions
for the qualified installer
2.3 Regulations and conditions
• Perfect function and operational reliability
can only be guaranteed with original Stiebel
Eltron accessories and spare parts intended
for the fitting.
• Any conditions specified by the water supply
company concerned must be respected.
• The water heater must not be subjected to
any water pressure, and the water connec-
tions must not be confused, since otherwise
the heater will leak.
• A flow pressure of up to 0.6 MPa is permis-
sible. Above 0.6 MPa, a pressure reducing
valve is to be installed in the main pipe.
Non-pressurised water heaters must
not exceed the following flow rates
with the valve fully opened:
5 l/min with a 5 l heater
10 l/min with a 10 l heater
If the flow rates are exceeded, the choke pro-
vided (10) is to be installed in the cold water
pipe.
• Flush the cold water inlet pipe through
thoroughly.
• The connection pipes and hoses of the fit-
tings must not be kinked
• If the copper pipes for the fittings WST and
WSM need to be shortened, the pipes are to
be internally deburred.
2.4 Installation of the fitting
A
WST / WSM on basin
» Insert the fitting body (
4
) with the sealing
ring into the basin, and secure it from be-
neath with the counterscrew and clamping
sleeve (
6
).
» Place the pivoting outlet (
1
) in position and
screw it tight.
B
WUT / WUM on kitchen sink
» Insert the fitting body (
4
) with the sealing
ring into the kitchen sink (max. plate thick-
ness 50 mm), and secure it from beneath
with the counterscrew and clamping sleeve
(
6
). In order to stabilize the standing surface
of the fitting, use the plastic shaped compo-
nent (
11
).
» Place the pivoting outlet (
1
) in position and
screw it tight.
2.5 Water connection
C
» Cold water inlet pipe (7.1
or
7.2
respectively
)
Connect the short cold water inlet pipe or
hose, marked “blue” (arrow points up-
wards) to the angle valve. When doing this,
insert the choke (10) into the pipe.
» Cold water pipe to water heater (8.1
or
8.2
respectively
)
Screw the pipe marked “blue” (arrow points
downwards) to the heater input socket.
» Hot water pipe from heater (9.1
or
9.2
re-
spectively
)
Screw the pipe marked “red” (arrow points
upwards) to the heater output socket.
» Filling the water heater
WST
and
WUT
Set the temperature adjustment tap to the
maximum temperature (as far as the left-
wards stop) and open the tap valve, wait
until water emerges at the outlet, and only
then switch the device on.
WSM
and
WUM
Open the left-hand tap valve, wait until the
water emerges at the outlet, and only then
switch the device on.
