Daikin D2CND028A1AB, Installation Manual

4 Installation

Installation manual

11

D035A1/4AB + D035A4AB
Wall-mounted condensing boiler
3P469346-5N – 2019.11

4.4

To mount the unit

1

The  mounting  template  shows  the  position  for  the  horizontal
flue. If there is no hole in the wall for the flue piping, drill one. If
there  is  already  a  hole  in  the  wall  for  the  flue  piping,  you  can
use this hole as a starting point to determine the position of the
mounting  bracket,  according  to  the  template.  Flue  duct  must
incline  3°  away  from  the  unit,  to  allow  the  condensate  to  drain
back to the boiler.

220

220

148

DN100

>3°

>3°

2

Drill  holes  for  the  mounting  bracket  (Ø10  mm).  Fasten  the
mounting bracket to the wall according to mounting template.

d=10 mm

3

Hang  the  unit  on  the  bracket.  Make  sure  the  unit  is  latched  to
the bracket.

4.5

Central heating system
requirements

Expansion vessel sizing

The  boiler  is  equipped  with  an  10  litre  expansion  vessel  that  has
initial charge pressure of 1 bar.

Sufficiency  of  the  incorporated  expansion  vessel  for  the  central
heating  circuit  that  the  boiler  is  to  be  connected  to  depends  on
system  charge  pressure  and  water  temperature  circulating  in  the
circuit.

Determination  of  system  water  height  and  related  system  charge
pressure are given below:

h

p

≤6 m

0.8 bar

7 m

0.9 bar

8 m

1.0 bar

9 m

1.1 bar

10 m 1.2 bar

11 m

1.3 bar

12 m 1.4 bar

13 m 1.5 bar

h

h

System water height (m)

p

System charge pressure (bar)

In  case  system  charge  pressure  needs  to  be  more  than  1  bar,  gas
side initial charge pressure must be increased to the pressure value
that  is  equal  to  system  charge  pressure.  Make  sure  that  gas
charging  to  the  vessel  is  done  while  boiler  and  circuit  are  not
pressurized.

According  to  the  graph  below,  there  is  no  need  to  install  an
additional  expansion  vessel  for  the  systems  with  a  water  volume  in
the  area  below  the  operating  temperature  curve.  If  water  volume  is
above  the  curve,  additional  vessel  must  be  installed,  preferably  on
the return to the boiler.

600

500

400

300

200

100

0

0,8

B (bar)

0,9

1,0

1,1

1,2

1,3

1,4

1,5

50°C - 30°C

50°C - 40°C

60°C - 40°C

70°C - 50°C

80°C - 60°C

A (l)

A

System water volume (l)

B

System charge pressure (bar)

*

50°C-40°C temperature regime is given for underfloor
heating systems

Water treatment

Inappropriate  central  heating  circuit  water  reduces  functionality  and
efficiency of the boiler over time. Appropriate water should have:

▪ pH degree between 6.5 and 8.5

▪ Hardness less than 15°fH and 8.4°dH

Appropriate additives can be used for water treatment.

If antifreeze is needed for the system, the chosen antifreeze should
not  interact  with  rubber,  commercial  plastic  and  metal  parts  of  the
boiler that are in contact with the central heating water.

For use of any additive in the central heating system, please refer to
the instructions of their manufacturers to ensure above functionality
and compatibility.

Water  softening  for  domestic  water  circuit  is  recommended  if
hardness  of  supply  water  is  higher  than  20°fH,  in  order  to  prevent
damage on boiler.