66
13 - MAINTENANCE
13.11 - Draining the
heating side of the
boiler
To drain the heating side of the boiler
follow the steps below:
allow the water inside to cool by
switching off the room thermostat
and turning knob “33” in figure 1 to
minimum. Wait until the display,
item “31” in figure 1, shows a
temperature less than 104
°
F
(40
°
C)
;
turn off the boiler;
shut off electrical power to the
boiler;
close the manual gas shutoff valve,
figures 16 and 17 item “3”;
close the boiler isolation valves in
the heating system. If isolation
valves haven’t been installed the
entire heating system will have to be
drained.
close the heating system fill valve;
follow the steps in section 13.2 or
13.3, to gain access the internal
components;
connect a hose to the boiler drain
valve and place the other end in a
sink or some other suitable drain;
open the boiler drain valve and drain
the boiler;
if boiler isolation valves have not
been installed in the heating system
open any bleed valves at the highest
point of the system;
after draining out all the water, close
the bleed valves and the boiler drain
valve;
WARNING!!! Do not recover and/or
re-use water drained from the
heating circuit for any purpose as it
could be contaminated. Failure to
comply with this warning can
cause extensive property damage,
severe personal injury or death!
13.12 - Draining the
domestic hot water
side of the boiler
To drain the domestic hot water side of
the boiler follow the steps below:
turn off the boiler;
close the valve in the water main
supplying the DHW system;
open all the hot and cold faucets in
the building;
if there isn’t a faucet or drain valve
below the boiler level, disconnect
DHW connections 10 and 12 in
figure 1.
13.13 – Overrides
To carry out specific checks covered in
the manual, it is possible to override
the control logic of the boiler. See the
next:
13.13.1 - Auto-
purging
To reset the auto-purging procedure
press the
and
keys
together for 10 seconds. When the
blinking
appears on the display,
press
.
13.13.2 - Fan
To run just the fan at full speed press
the
and
keys together
for 10 seconds, until the blinking
appears on the display. The fan will run
at full speed for 10 minutes. To shut
the fan off before the 10 minutes is up
press the
key.
13.13.3 – Minimum
and maximum
output
The boiler can be run at its’ minimum
or maximum output in both the heating
and domestic hot water modes by
following the steps below:
generate a demand for the mode to
be overridden:
- for heating turn up the room
thermostat and turn knob “33” in
figure 1 to its’ maximum;
- for domestic hot water turn knob
“32” in figure 1 to its’ maximum
and fully open a hot water faucet;
press the
and
keys
together for more than 10 seconds,
until a blinking
appears on the
display;
press the
key until the
display shows:
-
for minimum heating output;
-
for maximum heating
output adjusted by P parameter,
see section 11.10;
-
for maximum heating
output;
-
for minimum DHW output;
-
for maximum DHW output;
press the
key in order to
restore the boiler to normal running
conditions.
13.13.4 – Checking
the flame current
While running at the minimum and
maximum output described in section
13.13.3, the display will show the letter
of the mode checked. In the second
part of the display the value of the
ionization current will be shown. 30
corresponds to a current of 1 uA, 99 to
a current of 5.5 uA. The flame current
must always be at the correspondent
value as shown in section 14, header
“ionisation current”. If the value is not
within the above values, check:
a - positioning of the flame sensor
electrod as per section 13.5;
b - CO2 content as per section 11.9;
c - combustion air pressure as per
section 11.8.
Summary of Contents for ONEX
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