3
Product description
Installation and operating instructions
10
Daikin/ROTEX A2 F
Oil condensing boiler A2 F
008.1546499_02 – 04/2018 – EN
Item
Designation
Item
Designation
15
Blow-off line from
safety valve
DS
Pressure sensor
16
Cable penetration
STBK
Safety temperature
limiter
17
Burner
tv1
Inflow temperature
sensor
18
Boiler control panel
t
v2
Internal mixer sensor
19
Boiler main body with
heat and sound insula-
tion
t
R
Return flow temperat-
ure sensor
20
Type plate with manu-
facturer's number
Tab. 3-1
Legend for
Fig. 3-1
to
Fig. 3-7
3.2
Brief description
The A2 F is a completely pre-assembled oil condensing unit.
Operating mode
The A2 F is constructed so it can be operated independent of the
ambient air (concentric flue gas/air supply pipes). All flue gas carry-
ing parts are surrounded by combustion air. The burner suctions the
combustion air directly in through an installation shaft or a double-
walled flue gas pipe. This operating mode is recommended by us
and has many advantages:
▪ The heating room does not need any ventilation opening into the
open air and therefore does not cool down.
▪ Lower energy consumption.
▪ Additional energy recovery in the flue gas pipe through preheating
the combustion air.
▪ Contamination from the environment of the burner are not suc-
tioned in. The heating room can thus be used as a workspace,
laundry room, etc. at the same time.
▪ Possible to install in loft areas or attic.
▪ Possible to install in garages.
The heating water is first fed into the boiler body at the lowest posi-
tion. There, it is heated in counterflow via the adjacent combustion
chamber and several stainless steel heat exchanger tubes that pass
through the boiler body. The heated heating water is fed from the up-
per connection of the boiler body to the inflow connection of the
boiler housing. The combustion gases flow through the heat ex-
changer tubes into the boiler body from top to bottom after flame re-
versal in the combustion chamber. These tubes contain turbulators
that improve heat transfer to the heating water.
The condensate produced is fed into the sewage system via the con-
densate siphon and then via a plastic pipe. Optionally, it can be
neutralised via the optional condensate box.
Smart Start function
The Smart Start function was developed to avoid frequent switching
of the burner when the requirement for room heating is low.
If the optional Smart Start kit (two steplessly controllable 3-way
valves) is installed in the A2 F, the Smart Start function can be used.
The requirement for room heating is therefore temporarily covered
by the heat stored in the hot water storage tank. The Smart Start
function remains active until the next request for hot water genera-
tion is pending.
The Smart Start function is automatically controlled by the RoCon
BF controller.
Safety management
The entire safety management of the A2 F is carried out by the elec-
tronic controller. If there is water shortage, oil shortage or undefined
operating conditions, there is a safety shutdown. A corresponding
fault signal provides an engineer with all the necessary information
for troubleshooting.
Electronic controller
An electronic digital controller combined with the burner "intelligent"
firing unit automatically controls all heating and hot water functions
for the direct heating circuit and an optional storage tank charging
circuit.
One or more mixed circuits can be connected and controlled via op-
tionally connected mixer modules RoCon M1.
All settings, displays and functions are carried out by the integrated
RoCon BF controller. The display and the operating elements make
operation easy.
A digital room controller (RoCon U1) is optionally available for
greater comfort. It can be used as a remote control and room ther-
mostat.
The controller can be connected to the Internet via the optional gate-
way (RoCon G1). This enables remote control of the A2 F by mobile
phones (by app).
Condensing technology
Condensing technology makes optimum use of the energy contained
in the heating oil. The flue gas is cooled down in the boiler – and in
the flue system with ambient air-independent operation in the con-
centric flue gas system – to the extent that the temperature is below
the dew point. A part of the water vapour generated through com-
bustion of the heating oil thus condenses. The condensation heat is
fed to the heating, as opposed to low-temperature boilers, which en-
ables efficiency rates of over 100% (based on the lower heating
value).
Fuel
The A2 F can be operated with standard or low-sulphur heating oil
(sulphur content <50 ppm). It is equipped for the combustion of heat-
ing oil with biogenic components. Mixing of bio-heating oil up to
10 % (B10) is permitted without further conversion.
INFORMATION
We recommend using EL low sulphur heating oil, in order
to achieve the highest efficiency and to keep the mainten-
ance expenditure low.
Condensate treatment unit
The condensate produced during combustion in an oil condensing
boiler has a pH-value of 1.8 – 3.7 when using heating oil that is not
low in sulphur.
The optional condensate preparation unit fulfils the following func-
tions:
▪ Removal of floating particles in the settling basin
▪ Neutralisation of the condensate in the Hydrolit-MG filter material
When using low-sulphur heating oil, the condensate can usually be
drained off into the sewage network without neutralisation. Please
refer to the regulations of the local water authorities.
