Hydraulic Checks; Maintenance Of The Dhw Tank (Integrated Dhw Models); Emptying The Hot Water Tank; Descaling - Fujitsu Waterstage Comfort Series Maintenance Document

Split system single phase type
5 Maintenance services
Ensure that the general electrical power supply has been
cut off before starting any repair work
5 1

Hydraulic checks

Warning : If frequent refills are required it is
essential that you look for any leaks.If filling and
re-pressurization are required, check what type of
fluid has been used initially.
Recommended filling pressure: 1 to 2 bar (Precise filling
pressure is determined by the manometric height of the
installation) Each year,
- Check the expansion vessel pressure (precharge 1
bar) and the correct functioning of the safety valve
- Verify the safety unit on the cold water supply inlet
Make it work as prescribed by the manufacturer
- Check the shut-off
- Verify the correct functioning of the distribution valve
5 2 Maintenance of the DHW tank (Integra-
ted DHW models)
Maintenance of the tank must be undertaken once
a year (The frequency may vary according to water
hardness)

5 2 1 Emptying the hot water tank

- Remove the facade from the hydraulic unit
- Close the cold water entry into the tank
- Open a hot water tap and open the water tank
emptying valve (ref 1)

5 2 2 Descaling

- Empty the water tank
- Remove the hood of the electrical back-up (ref 2)
- Disconnect the electrical back-up
- Unplug the ACI
- Remove the electrical back-up (ref 3)
- Remove any limescale deposits that have built up inside
the tank It is best to let the scale stuck to the walls of the
tank: it forms a protective layer
- Gently remove any limescale deposit on the glove
finger Do not use any metal objects or chemical or
abrasive products
- Replace the joint of the electrical back-up (ref 4) each
time it is dismantled
- Replace the electrical back-up and carry out 'crossed'
locking of the nuts
- Reconnect the electrical back-up
- Plug in the ACI
- Replace the hood of the electrical back-up
Maintenance document "1792 - EN"
figure 5 - Emptying the hydraulic unit and/or DHW
5 3

Checking the outdoor unit

- Dust off the heat exchanger if necessary, being careful
not to damage the fins.
- Straighten the vanes using a comb
- Check that there is nothing obstructing the passage
of air
- Check the fan
- Verify that condensate drain is not obstructed
• Checking the refrigeration circuit :
- When the refrigerant charge is in excess of 2kg (>10 kW
models), it is compulsory to have an approved after sales
service check the refrigeration circuit every year (with
a certificate of capacity for the handling of refrigerants
- Check the lack of leak (connections, valves...)
5 4

Electrical checks

- Check connections and possible tightening
- Check the cables condition and electronic boards
- ACI light: In normal operation, the light flashes.
tank
- 91 -