Connecting The Heating Circuit Hydraulically; General; Rinsing Out The Installation; Filling And Purging The Installation - Fujitsu 112 Installation And Operating Manual

Heat pump split single service 3 phase
2 8 Connecting
the heating circuit hydraulically

2 8 1 General

The connection must comply with good trade practice
according to local building regulations.
The heating circulating pump is built into the hydraulic
unit.
Connect the central heating pipes to the hydraulic unit,
complying with the direction of circulation.
The diameter of the pipes between the hydraulic
unit and the heating collector must be at least 1 inch
(26x34mm).
Calculate the diameter of the pipes according to the flow
rates and the lengths of the hydraulic systems.
Tightening torque : 15 to 35 N.m
Use union connectors to facilitate removing the hydraulic
unit.
Preferentially use connection hoses to avoid transmitting
noise and vibrations to the building.
Connect the drains from the drain valve and the safety
valve to the main sewer system.
Reminder: Seal everything when fitting in accordance
with prevailing trade practice for plumbing work :
- Use suitable seals (fibre seals, o-rings).
- Use Teflon tape or hemp.
- Use sealing paste (synthetic depending on the case).
The use of glycol is not necessary. If you are using a
glycol/water mix, provide for an annual check on the
quantity of glycol.
In certain installations, the presence of different metals
can cause corrosion problems ; the formation of metal
particles and sludge in the hydraulic circuit is then
seen.
In this case, it is advisable to use a corrosion inhibitor in
the proportions indicated by its manufacturer.
It is also necessary to ensure that the treated water
does not become aggressive.
Figure 24 - Release of the
circulation pump
Installation and operating manual "1364 - EN"

2 8 2 Rinsing out the installation

Before connecting the hydraulic unit to the installation,
rinse out the heating system correctly to eliminate
any particles that may affect the appliance's correct
operation.
Do not use solvents or aromatic hydrocarbons (petrol,
paraffin, etc.).
In the case of an old installation, provide a sufficiently
large decanting pot with a drain on the return from the
boiler and at the lowest point in the system in order to
collect and remove the impurities.
Add an alkaline product to the water and a dispersant.
Rinse the installation several times before filling it
definitively.

2 8 3 Filling and purging the installation

Check the pipe fixings, the tightness of the connectors
and the stability of the hydraulic unit.
Check the direction in which the water is circulating and
that all the valves open.
Proceed to fill the installation.
Do not operate the circulating pump while filling. Open
all the drain valves in the installation and the bleeder
valve for the hydraulic unit to remove the air contained
in the conduits.
Close the drain and bleeder valves and add water until
the pressure in the hydraulic circuit reaches 1,5 bar.
Check that the hydraulic circuit has been purged
correctly.
Check that there are no leaks and that the circulating
pumps are not seized (if need be, release them).
After the "Start-up" stage (see
machine has started, purge the hydraulic unit again
(2 liters of water).
Figure 25 - Recommended
circulation speed (for radiator)
page 28), once the
(P)
Figure 26 - Hydraulic
unit bleeder valve
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