13 - use – Slant/Fin VSL-160C Part C User Manual

Page 7

13.18.1 - Diagnostics: “L” lock-outs

“L”
Code

Lock-out
description

Checks to make

Solutions

L01

L02

L03

L04

13 - USE

L05

L06

L07

L08
L09
L10
L12
L13
L14
L15
L16

No fl ame detected after
three ignition attempts.

L17

Flame extinguishes three
times.

Boiler temperature is over
203° F (95°C).

Gas valve command relay

Safety relay

Flue gas sensor over
210°F (99°C)

Electrical circuit of fl ue
gas sensor is interrupted

Spark generator relay

RAM memory

E2prom memory damaged

Program error

The temperature
difference between the
U1 and U6 sensors is too
great

Check:
a-correct gas supply pressure (see

section 12.7);

b-ignition spark (see section 14.4);
c-correct combustion air pressure (see

section 12.8);

d-120Vac at the gas valve;
e-resistance of the two gas valve coils

should be 0.18 kohm and 1.1 kohm;

f- If the burner lights, but goes out at the

end of the ignition attempt, check: that
the ionization current is set at a value
greater than 60 (follow procedure in
section 14.12.4)

Check:
a-that the ionization current is set

at a value greater than 60 (follow
procedure in section 14.12.4);

b-check that gas valve open fast

enough;

a-Check that the circulator pump is
working;
b-Check if the water fl ow is not less than
5 GPM

Check for correct polarity of the wires to
the pump. Try to switch the wires.

Check:
a - that the electrical resistance of the
fl ue gas sensor complies with the graph
in Section 14.13;
b - that the effi ciency of the boiler is
over 86%

Check that the electrical resistance of
the fl ue gas sensor corresponds with the
graph in section 14.13;

Check that:
a - the electrical resistance of the two
sensors corresponds with the graph in
section 14.13;
b -check that the heating water fl ow is
not too low.

a-If the gas supply pressure is incorrect, it must be adjusted to

the correct pressure;

b-If spark is not present, check for correct ignition ectrode

position and gap as per section 14.4; If position is correct,
check for 120Vac at the supply of the spark generator.

c-if the combustion air pressure is incorrect, inspect the vent

system and eliminate any obstructions;

d-if the voltage to the gas valve is not 120Vac the power control

board must be replaced;

e-if the resitance of the gas valve coils is not 0.18 kohm and/or

1.10 kohm, the gas valve must be replaced.

f-If the ionization current is not greater than 60, confi rm that

the the CO2 content is adjusted properly (see section
12.9). Check the fl ame detection electrode (section 14.4)
and if necessary replace it, check the integrity of the fl ame
detection electrode electrical wires.

a-If the ionization current is not greater than 60, confi rm that

b-Following procedure as per Section 14.12.4, check few times

if passing from low fi re to high fi re the fl ame estinguish. If
estinguish, change the gas valve.

a-If the circulator pump is bad, replace it, if is good, replace the
power control board.
b-If the water fl ow is less than 5 GPM check for any zone
valves that must be opened.

Replace the power control board

If the pump won’t run replace it. If the pump is good try to
replace the power control board.

a-If the fl ue gas sensor resistance does not correspond with the

correct values, replace it;

b-if the boiler effi ciency is less than 86% and the CO2 content

is correct, the primary heat exchanger has to be replaced
and proper water treatment methods employed to prevent
mineral build up on the water side

If the sensor resistance does not correspond with the correct
values, replace it;

Replace the power control board

a-If one or both sensors does not have the correct resistance

value, it must be replaced;

b-If temperature difference between U1 and U8 is higher than

55°F at maximum input, the heating water fl ow rate is too
low. The heating water fl ow rate must be corrected.