Hoval Max-3, Operating Instructions Manual, Page: 81 / 88

MAINTENANCE AND INSPECTION (HEATING SYSTEM)
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9. Maintenance and inspection (heating
system)
The work described below is normally perfor-
med by the heating specialist in the course of
annual maintenance. Nevertheless, carry out
the following checks during the year and per-
form the work described as necessary.
9.1 Checking the water pressure
NOTICE
• If the system water pressure is too low
(check pressure gauge (Fig. 02)), top it up
with water (chapter 9.2) or inform your hea-
ting specialist.
• Danger of corrosion due to frequent top-
ping up (more than 1x/year) – contact the
heating specialist.
• Complete filling and draining must be per -
formed by the heating engineer.
Min. Max.
Fig. 02
9.2 Top up with water
The replacement water must be of the required quality.
The quality requirements are stated in the installation in-
structions in the “Water quality” chapter (paragraph: Fil-
ling and replacement water). If the heating system is filled
with frost protection agent or treated water, the heating
specialist's instructions must be followed.
Procedure
1. Set the blocking switch to “0” and disconnect the heat
generator from the mains (main switch, fuse, etc.)
2. The mixing valve (manual adjustment) and the shut-
off valves in the heating flow and return must be open
3. The connection between the filling valve and the wa -
ter tap is made using a hose: fill the hose with water
before establishing the connection to prevent any air
from entering the heating system
4. Slowly fill with water while checking the water level on
the pressure gauge
5. Open the bleed valves after topping up until all the air
has been vented from the heating system
6. Unscrew the hose again after filling to break the con -
nection reliably
7. Check the water pressure again
8. Switch the system on again