- 26 -
INSTALLATION
- Isolating valve :
It is advised to place isolation valves on the ins-
tallation’s flow-returns so as to allow possible ser-
vicing on the boiler without draining the
installation.
Never place an isolation valve
between the safety control box and the hot
water tank
- For the FCX domestic hot water produc-
tion system - See the tank technical instructions.
- Circulating pump :
Water circulating pumps provided in the various
circuits must be large enough for each circuit in-
cluding the pressure drop of the boiler/condenser
in the unit.
Set the pump to the speed that is appropriate to
the installation’s flow rate and load loss (limitation
of circulation noises, optimisation of power
consumption).
- Water pressure gauge (not supplied):
This has to be fitted outside the unit.
- Safety valve:
This must be connected to the used water drain
via a siphon funnel.
- Expansion vessel:
If the installation capacity is over 62 litres (16 gal),
an extra expansion vessel to the boiler expansion
vessel will be added.
The correct operation of the boiler requires an
installation pressure of at least 1 bar.
If the installation is a renovation and uses an
open vessel, this must be removed and replaced
with a closed vessel (the boiler can be equipped
with one originally) to seal the circuit.
The vessel should be able to support an expan-
sion of 6% of the total water capacity of the hea-
ting circuits. But it is important to note, in order to
guarantee this expansion, that the useful capacity
of a vessel does not equal its actual capacity.
Example
:
• Installation : 100 litres (26.4 gal)
• Domestic hot water tank : 5 litres (4.3 gal)
• Boiler : 16 litres (4.2 gal)
• Total water capacity : 121 litres (32 gal)
Conditions
: Using a vessel pre-loaded to 1 bar
(14.5 Psi) (under floor boiler =
ground floor h 1 floor), hea-
ting safety valve calibrated at
3 bars (43.5 Psi), installation filled
cold at 1 bar.
• Vessel efficiency calculation (R):
+ 1) = the transformation of relative pressures into
abolute pressures
• Calculation of the useful capacity of the vessel
(Cu) :
• Calculation of the real capacity of the vessel
(Cr) :
8.2 - Accessories to connect, install or
adjust
19
24
18
22
FC
X
-6
4
-U
Fig. 23
- 1 Expansion vessel (22),
- 1 Circulating pump (18),
- 1 Safety pressure relief valve (19),
- 1
Safety valve outlet
(24)
R
Safety Pressure - Filling pressure
Safety Pressure
------------------------------------------------------------------------------------
=
R
3
1
+
1
1
+
–
3
1
+
----------------------------------------
0 5
=
=
Cu
total volume
expansion
=
Cu
121
0 06
7 26dm
3
=
=
Cr
Cu
R
-------
=
Cr
7 26
0 5
------------
14 5 litres (3.83 gal)
=
=
