- 9 -
MAINTENANCE
4 - CHECKING ACCESSORIES
- Check that the safety and control devices (3 bar
safety valve, air bleed, safety control box, etc.)
are operating properly.
- Clean the condensate drain siphon and then fill it
with water.
- Also check that neither the installation nor the
boiler present any water or fuel leaks (leaks may
produce a risk for safety and shorten the lifes-
pan).
- When it is frequently necessary to add water to
maintain pressure in the installation, even though
no leaks have been discovered, perform an ex-
pansion vessel check (section 5 - page 9 -
chapter II - MAINTENANCE - SERVICING MA-
NUAL).
5 - EXPANSION VESSEL PRE-INFLATION PRESSURE CHECK
- Drop the pressure in the heating installation by
opening the drain cock or the safety valve (pres-
sure gauge reading under 0.5 bar).
- Check the pressure in the expansion vessel and
if necessary bring it back up to pressure, or repla-
ce it if the membrane is punctured (water present
in the inflating valve).
- To optimise the efficiency of the vessel:
• adjust its pre-inflation pressure in line with the
installation. It must correspond to the static hei-
ght of the installation (H) expressed in bars
(height between the highest point of the instal-
lation and the expansion vessel, with 10 me-
tres = 1 bar),
• adjust the filling pressure of the installation to a
value of over 0.2 bar above the pre-inflation
pressure of the vessel (after totally bleeding
the air from the installation).
6 - COMBUSTION PRODUCT CONDUITS (FLUE)
- Check the combustion product evacuation con-
duit and the air inlet conduit at least once a year
(airtightness of the parts that may be disassem-
bled - conduits not obstructed).
7 - DRAINING
7.1 - Draining the boiler
- Cut the power supply,
- turn off the gas cock,
- turn off the heating flow/return valves (if they are
fitted),
- connect the drain valve (18) to the sewage sys-
tem,
- open the drain valve.
Ensure that the air bleed (item. 16) is
open, as soon as the pressure gauge in-
dicates a zero pressure to allow air to
enter the boiler shell.
7.2 - Draining the hot water tank
- Close the hot water supply valve of the network,
- open a hot water tap to make the pressure drop,
- remove the access flap (33) to allow air to enter
the tank (26),
- connect the drain valve (36) to the sewage sys-
tem,
- open the drain cock (36) at the bottom of the tank.
!
TH
I-
98-
0
16
18
Fig. 6
T
IO-24-
0
26
33
36
Fig. 7
Summary of Contents for THI 2-17 B 120
Page 19: ... 19 V PARTS LISTS THI 2 17 B 120 ...
Page 23: ... 23 PARTS LISTS CONTROL BOX ...
