Rotex GCU compact 315, Installation And Maintenance Instructions Manual

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3 x Product description
14
FA ROTEX GCU2 - 06/2017
Tab. 3-1 Legend for fig. 3-1 to fig. 3-7
3.2 Brief description
The ROTEX Gas Combi Unit 2 (GCU compact) is a fully preas-
sembled gas condenser unit integrated in a hot water storage
tank. The excellent thermal insulation properties of the plastic
storage tank ensure that heat losses are kept to a minimum. The
aluminium boiler body is in a metal housing inserted into the
cover of the storage tank. The complete flue gas unit is sur-
rounded by fresh air.
Operating mode
The ROTEX GCU compact is designed so that it can be operated
ambient air-independent (concentric flue gas/supply pipes). The
burner suctions the combustion air directly in through an instal-
lation shaft or a double-walled flue gas pipe. This method
operation is recommended by ROTEX and has many advan-
tages:
– 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 pre-
heating the combustion air.
– Contamination from the environment of the burner are not
suctioned in. The heating room can thus be used as a work-
space, laundry room, etc. at the same time.
– Possible to install in loft areas or attic.
The accumulated condensate is collected in the flue gas collector
and transported through a plastic pipe into the storage tank
where it is neutralised.
The unpressurised storage tank water acts as the heat storage
medium. Useful heat is supplied and removed via the spiral heat
exchanger, which is made from a stainless steel corrugated pipe
(1.4404), and is completely immersed in the storage tank water.
The hot water zone in the storage tank works as a combination of
heat storage and geyser (see fig. 3-3 and fig. 3-6).
The cold water which flows out when the hot water is removed is
first routed to the storage tank at the very bottom of the heat ex-
changer, where it cools the lower area of the storage tank down
as much as possible. The readiness zone is flowed through and
heated from top to bottom by the
heat exchanger for the
storage tank charging (SL-WT) which is heated by the gas
burner.
On its way to the top, the domestic water continuously absorbs
the heat of the storage tank water. As the flow direction makes
use of the counter flow principle and the heat exchanger has a
spiral shape, there is definite temperature stratification within the
hot water storage tank. As high temperatures can be maintained
for a very long time in the upper section of the storage tank, a high
hot water output is achieved even if water is drawn off over a long
period of time.
– In the GCU compact 5xx (Biv) models, the SL-WT ends
approx. 40 cm above the floor of the container. Only the hot
water zone above that point is heated by the boiler. The water
below that point in the tank is heated by solar power alone.
– In the GCU compact 3xx (Biv) models, the SL-WT descends
to the floor of the container. The entire storage volume is
heated by the boiler (greater hot water output readiness).
1 Cold water connection (1" AG)
2)
2 Hot water connection (1" AG)
2)
3 Storage tank - inflow (1" AG)
4 Storage tank - return flow (1" AG)
5 Heater - inflow (1" AG)*
2)
6 Heater - return flow (1" AG)*
7 Solar - inflow (1" IG)
8 Drain connection or

Solar - return flow
9 Flue gas
10 Supply air
11 Sensor immersion sleeve for storage tank
temperature sensor t
DHW
12 Upper filling connection and condensate
overflow connection
13 Condensate drain hose (on the building
side)
14 Condensate pipe
15 Heating heat exchanger (boiler body)
16 Heat exchanger (stainless steel) for do-
mestic hot water heating
17 Heat exchanger (stainless steel) for stor-
age tank charging and heating support
18 Heat exchanger (stainless steel) for biva-
lent storage tank charging
1)
19 Biv storage tank charging - inflow
1)2)
(1" IG)
20 Biv storage tank charging - return flow
1)2)
(1" IG)
21 Solar - inflow layering pipe
22 Heating circulation pump
23 Burner blower
24 Safety pressure relief valve (heating cir-
cuit)
25 Vent valve (manual)
26 Gas connection (G ½" IG) with connected
gas hose
27 Boiler control panel with RoCon BF con-
troller
28 Thermal insulation
29 Panelling of the heat cell
30 Cover
31 Holding burls for protective cover
32 Type plate
33 Settings type plate
34 Threaded insert for carrying loop
35 Combined filling and draining valve (heat-
ing circuit)
36 Automatic vent valve
37 Fill level indicator (tank water)
38 Electrical connection of Backup heater
BUxx
39 Ball cock (heating circuit)
40 MAG connection
3UV DHW

3-way valve (distribution valve, hot wa-
ter/heating/heating support)
3UVB1

3-way valve (mixer valve)
t
DHW
Storage tank temperature sensor
t
R
Return flow temperature sensor (boiler cir-
cuit)
t
V1
Inflow temperature sensor (boiler circuit)

t
V2
Internal mixer sensor = inflow temperature
sensor (heating circuit)
A Gas boiler
B Storage tank (polypropylene double walled
jacket with PUR hard foam heat insulation)
C Pressure-free storage tank water
D Hot water zone
DS Pressure sensor
E Solar zone
FLS

Flow sensor (boiler circuit)
MAG

Diaphragm expansion vessel (on the build-
ing side)
RPS4

Optional: ROTEX Solaris R3 control and
pump unit
AG External thread
IG Internal thread
ÜM Union nut
Safety devices
Observe tightening torque!
* Ball cock (1" IG) is supplied.
1)
Only valid for types with Biv configuration
2)
Recommended accessories:

Circulation brake SKB (2 pcs each),
16 50 70