4
combination boiler -
Installation and Servicing
GENERAL
1
BOILER WATER CIRCUIT DIAGRAMS
INTRODUCTION
The
europa
combi boiler
is a fully automatically controlled,
wall mounted, low water content, fanned flue combination gas
boiler.
Note.
Due to the high efficiency of the boiler a plume of water vapour
may form at the terminal during operation.
Central heating (CH) output is fully modulating with a range of:
11.1 to 24.3 kW (37,800 to 82,900 Btu/h) for
europa 24
12.6 to 28.0 kW (43,000 to 95,500 Btu/h) for
europa 28
Instantaneous Domestic hot water (DHW) output is also fully
modulating with a maximum of:
24.3 kW (82,900 Btu/h) for
europa 24
28 kW (95,500 Btu/h) for
europa 28
The boiler is supplied fully assembled with DHW built in heat
exchanger, diverter valve, circulating pump, pressure gauge,
safety valve and CH expansion vessel.
Variable CH and DHW temperature controls are fitted on the
user control.
The boiler casing is of white painted coated mild steel.
The boiler temperature controls are placed at the botton of the
front panel.
The heat exchanger is of finned oval copper tubes.
The boiler is suitable for connection to fully pumped, sealed
water systems ONLY.
The system pipework MUST include drain cocks in appropriate
places.
Pipework from the boiler is routed downwards as standard, but
may be routed upwards behind the boiler using the stand-off
frame (supplied in a separate kit).
OPERATION
With no demand for CH the boiler fires only when DHW is
drawn off.
When there is a demand for CH, the heating system is
supplied at the selected temperature of between 45
o
C and
82
o
C, until DHW is drawn off. The full output from the boiler is
then directed via the diverter valve back to the heat exchanger to
supply a maximum DHW draw-off at 35
o
C temperature rise of:
- 10.0 l/min for
europa 24
- 11.5 l/min for
europa 28
At low DHW draw-off rate the maximum temperature is limited
to 62
o
C by the modulating gas control.
Refer also to Frame 1 - 'Boiler Water Circuit Diagrams'
Central Heating Circuit
Domestic Hot Water Circuit
Fan
Expansion
vessel
Diverter
valve
C.H.
Temperature
sensor
H.L.
Termostat
Air Pressure
Switch
Low
Pressure
switch
Heat
exchanger
Burner
Flame sensing
electrode
Ignition
electrode
Pump
Automatic
air vent
Gas valve
Safety
relief valve
CH Flow
Gas
CH Return
Fan
Diverter
valve
Air Pressure
Switch
Heat
exchanger
Flame sensing
electrode
Ignition
electrode
Gas valve
Gas
H.L.
Termostat
Burner
Pump
Automatic
air vent
Safety
relief valve
Flow rate
switch
DHW Cold in
DHW Hot out
DHW
Temperature
sensor
Flow
restrictor
Cold water
filter
Low
Pressure
switch
Venturi
Venturi
Manual
air vent
Manual
air vent