452114.66.95 · FD 9801
EN-9
DFM 1988
English
4 Operation
4.1 Mode of operation
If the water exchanger requirement in the domestic water instal-
lation is not fulfilled within 3 days, a switch output is released to
control a second heat generator, which enables heating up to a
domestic hot water temperature of > 60 °C, e.g. via electric sup-
plementary heater CEHK. The increased threshold is maintained
until the requested water exchange has taken place within 72 h.
The switch output for the second heat generator is active, until
the switch-off temperature of 62 °C is achieved (switch-on takes
place at 60 °C).
4.2 Setting of the cylinder volume
To set the cylinder volume, the S1 key (see Fig.5.1 on pag. 10) is
pressed and held down when applying the supply voltage. Each
actuation of the S1 key switches the code further
Code setting via volume of water to be drawn:
Code 1: volume of water to be drawn within 3 days must be
greater than 350 l
Code 2: volume of water to be drawn within 3 days must be
greater than 450 l
Code 3: volume of water to be drawn within 3 days must be
greater than 800 l
Code 4: not used
Code setting via cylinder size (capacity):
Cylinder size in the domestic hot water installation:
Code 1 for a capacity of up to 350l
Code 2 for a capacity of up to 450l
Code 3 for a capacity of up to 800l
The capacity corresponds to the domestic hot water quantity
stored in the cylinder. In cylinders with internal heat exchangers,
this is lower than the cylinder volume.
NOTE
º
The next highest cylinder size should be selected for interim values.
Fig. 4.1:Code 1-4
4.3 Function test
After a voltage reset, the total added volume of water to be drawn
of the DFM 1988 is reset. I.e. the flange heater is activated until
one of the following switching conditions is fulfilled.
Temperature on the domestic hot water outlet sensor ex-
ceeds 62 °C
Set minimum volume of water to be drawn is taken
