Pipe Installation; Maintenance; Dealing With Malfunctions - Nibe EKS 750 Installation And Maintenance Instructions Manual

Pipe installation

The water heater must be supplied with shut-off, non-
return, safety and vacuum valves according to applicable
norms. A drain plug should also be installed to facilitate
draining.
The water heater must be supplied with a mixer valve,
which limits the temperature of outgoing hot water to
60 °C. If this valve is not fitted, some other measure
must be taken to prevent the risk of scalding.
The safety valve must be set to maximum 9 bar
(0.9 MPa) and the overflow pipe must run freely over
the drain. The size of the overflow pipe must be the
same as on the safety valve. The overflow pipe must be
routed downwards to prevent water pockets and to be
frost proof. The outlet of the overflow pipe should be
visible.
Electrical connections
NOTE!
Electrical installation and service must
be carried out under the supervision of
a qualified electrician.
The hot water heater has three immersion heater con-
nections for a maximum output of 3 x 9 kW. Separate
supply from group central is routed to each immersion
heater.
Each immersion heater is supplemented with junction
box type K (2 pole thermostat, 3 pole temperature
limiter).
Do not modify or reconnect!
NOTE!
The hot water heater must be com-
pletely filled with water before it is
connected on the electrical side.
Filling
The hot water heater is filled by first opening a hot
water tap in the system and then opening the shut off
valve on the incoming cold water. This valve should
then be fully open during operations. When only water
comes out of the hot water tap (initially an air-water
mixture comes out of the tap) can the tap be shutoff
and the water heater is filled.
Installation and maintenance
Emptying
Turn off the power to the heater.
n
Shut off the incoming cold water.
n
Open the drain connection, or the drainage valve if
n
fitted.
During draining air must be let into the heater by loos-
ening a hot water heater connector or a hot water
tap. To ensure the complete emptying of the hot water
heater, a hose or pipe with outlet running under the
lowest level of the heater must be installed on the drain
connection or drain valve. When mounted in locations
exposed to the risk of frost, the hot water heater must
be emptied whenever not in operation. Freezing will
result in the heater bursting.

Maintenance

The safety valve must be inspected regularly, about 4
times a year, to prevent clogging. The check is made by
opening the safety valve manually, water should then
flow through the overflow pipe. If this does not happen
then the safety valve is defective and must be changed.
The safety valve sometimes releases a little water after
hot water has been tapped. This discharge is caused
by the expansion of the cold water taken into the wa-
ter heater, resulting in a pressure increase, whereby the
safety valve opens.

Dealing with malfunctions

If the water fails to heat up, check the fuses in the
distribution box. If none of the fuses have blown, the
reason may be that the temperature limiter has tripped
as a result of a fault in the hot water heater. Once the
fault has been remedied, the temperature limiter can
be reset. This must be done under the supervision of a
qualified electrician.
Service
When a service is necessary, contact the main contrac-
tor; you will need, under all circumstances, to state the
manufacturing number (95) and installation date.
Only equipment supplied by NIBE AB in Markaryd may
be used.
EKS 750
GB
5