Slant/Fin VSL-160C Part C - Manual (Page 20)

92
14 - MAINTENANCE
14.10 - Draining the
heating side of the
boiler
To drain the heating side of the boiler
follow the steps below:
1. cool boiler turning knob “7” in
Figure 13-1 to 114°F (45°C). Wait
until the display, item “1” in Figure
13-1, shows a temperature less
than 114°F (45°C);
2. turn off the boiler;
3. shut off electrical power to the
boiler;
4. close the manual gas shutoff valve,
Figure 11-1;
5. 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.
6. close the heating system fi ll valve;
7. follow the steps in Section 14.2,
to gain access the internal
components;
8. connect a hose to the boiler drain
valve intem “4” in Figure 7-6 and
7-7, and place the other end in a
sink or some other suitable drain;
9. open the boiler drain valve and
drain the boiler;
10. if boiler isolation valves have
not been installed in the heating
system open any bleed valves at
the highest point of the system;
11. after draining out all the water,
close the bleed valves and the
boiler drain valve;
NOTICE: The boiler cannot be
drained completely of water without
purging the unit with an air pressure
of 15 psi.
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!
14.11 - Draining the
domestic hot water
side of the boiler
To drain the domestic hot water side
of the boiler follow the steps below:
1. turn off the boiler;
2. close the valve in the water main
supplying the DHW system;
3. open all the hot and cold faucets in
the building;
4. if there isn’t a faucet or drain valve
below the boiler level, disconnect
DHW connections “10” and “12” in
Figure 3-1.
14.12 – Overrides
To carry out specifi c checks covered
in the manual, it is possible to override
the control logic of the boiler. See the
following sections:
14.12.1 - Auto-purging
To reset the auto-purging procedure
press the and keys
together for 10 seconds. When the
blinking appears on the display,
press .
14.12.2 - 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.
14.12.3 – 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:
1. generate a demand for the mode to
be overridden:
- for heating turn up the room
thermostat and turn knob “7” in
Figure 13-1 to its maximum;
- for domestic hot water turn
knob “11” in Figure 13-1 to its
maximum and fully open a hot
water faucet;
2. press the and keys
together for more than 10 seconds,
until a blinking appears on
the display;
3. press the key until the
display shows:
- for minimum heating
output;
- for maximum heating
output adjusted by P parameter,
see section 12.10;
- for maximum heating
output;
- for minimum DHW output;
- for maximum DHW output;
4. press the key in order to
restore the boiler to normal running
conditions.
14.12.4 – Checking the
fl ame current
While running at the minimum and
maximum output described in Section
14.12.3, 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 fl ame current must always be at
the correspondent value as shown
in Section 15, header “ionisation
current”. If the value is not within the
above values, check:
a - positioning of the fl ame sensor
electrod as per section 14.4;
b - CO2 content as per section 12.9;
c - combustion air pressure as per
section 12.8.