E93.1001EN.C Manual CD
+
42
9.2
Control
T
ANK SENSOR
With the CD
+
water heater, a threaded sensor is supplied as tank sensor.
On a new ECO tank, this sensor can be mounted on the return pipe right away.
The use of this threaded sensor is also recommended for existing tank set-ups, because its con-
trolling behaviour is more stable than that of the strap-on pipe sensor.
When this threaded sensor is used on an existing ECO tank set-up, a reducing nipple may be needed, to be able
to mount the sensor on the return of the tank, provided that this return has a threaded socket, i.e. this ECO tank
is not older than from 2008.
On other tanks, generally the supplied threaded sensor cannot be applied; the existing pipe sensor must be kept
in use and be connected to the water heater control. Check that this sensor has been placed on one tank return,
as close as possible to this tank.
E04.016.677
Threaded sensor
(M5x5) with Molex connection.
E04.016.304
Strap-on pipe sensor.
•
Supplied with the water
heater, cable with Molex
connector included.
G
ENERAL CONTROL
There is no need for a sensor
in
the tank, because when the pump starts to run, the tank sensor of the
water heater is measuring the water temperature of the tank.
When no water is drawn from the tank, the tank sensor is measuring the water temperature in the tank.
After ending a heat demand, the pump has a post turning time.
On the control panel, the tank or hot water temperature can be set.
When an RCW remote wall controller is connected to the wire terminal (13) and (14), the setting of the
tank temperature can be done with this controller (Open Therm bus), also the night or weekend reduction
of tank temperature.
During a period of no tapping, the temperature inside the tank is maintained at the Setting temperature
automatically.
A safety control stops the water heater from firing, when the temperature difference between flow and
return gets higher than allowed at the actual load (flow monitoring/
ΔT function).
Parameters: the default of the parameters of the water heater control have been set for this type of tanks.
C
ASCADE CONTROL
Up to twelve water heaters can be cascaded.
One water heater has to be appointed master, the other water heaters are appointed slaves, each with his
own address in the software.
The slaves are connected with two wires to the master.
Every individual water heater has a connection for a pump.
An external tank sensor (S3) is placed at the inlet tube to the water heater(s) (see description on top of
this page) measuring the tank water temperature.
At a heat demand, the master water heater controls the heat output of the slaves, on base of the measured
temperature of the tank sensor.
When a slave stops burning, the pump connected to this slave has a post turning time.
When one water heater in the cascade installation is burning, the fans of the other water heaters are
turning at a low speed, preventing recirculation of the flue gases.
Flow monitoring cf. § 8.4 (page 39) remains active in every separate water heater of the cascade.
Parameters: for cascade parameters see § 10.17 pages 74 ff. (parameter menu C).
