Freestyle 2 Series Manual page 91

FreeStyle
®
2
series
37 Troubleshooting
Check flame signal
1. Navigate to Diagnostics/Inputs on the FreeStyle ® control
display (see pages 62 to 66 for navigation instructions.
2. The flame signal value must be at least 25 on low fire for a
FreeStyle ® 80, 120 or 155. The flame signal value must be
at least 255 on high fire FreeStyle ® 80, 120 or 155. , reading
at times 10 equals microamps of flame signal. If the flame
signal drops below this level, the FreeStyle ® control will at-
tempt to correct by increasing the blower speed to increase
flame signal.
3. A low flame signal may indicate a fouled ignitor or damaged
ignitor cable insulation.
a. See "Inspect ignition electrode, " page 111 to remove and
inspect the ignitor.
b. If required, clean the ignitor and flame rod as instructed,
see page 111.
c. If cleaning the ignitor does not improve, ground wiring
is in good condition, and ground continuity is satisfac-
tory, replace the ignitor.
4. If flame signal still remains low:
a. Inspect the vent and air piping.
b. Check combustion values.
c. Then inspect the heat exchanger, following the proce-
dures given in this manual for inspecting and cleaning
of the heat exchanger cover plate and other boiler com-
ponents (starting on page 111).
d. Clean the heat exchanger as described in this manual if
necessary, see page 114.
Check control fuse
See Replacement parts for fuses, page 123.
ALWAYS check circuit fuses before replacing
control or any major components (blower, etc.).
If a fuse is blown, it can prevent the control or
other components from operating.
1. Turn OFF power to boiler at external line switch. Then
remove the jacket door.
2. Locate fuses using Figure 115 and Figure 116.
3. Remove and inspect the fuses (Item a, Figure 115 or Item
b, Figure 116).
4. If necessary, replace the fuses:
a. Control circuit fuse is a 250 VAC 3.15-amp rated fuse.
(Part number 640-000-122)
b. Thermostat-relay circuit fuse is a 250 Volt 630mA rated
fuse. (Part number 640-000-123)
Do not jumper fuses or replace with any fuse
except as specified. Failure to comply could result
in severe personal injury, death or substantial
property damage.
Checking temperature sensors
1. The boiler temperature sensors (flue, outdoor, return water
and supply water) are all resistance-type devices. Figure 117
shows the correct value for the sensor at various tempera-
tures. For dual sensors, the temperature difference between
the sensors must be no more than 10 °F. (Supply outlet 200
sensor).
2. Use the resistance values at 32°F, 60°F, 70°F and 212°F to
measure the sensor resistance at known temperatures (ice
point, room temperature and sea level boiling point). For
ice point and boiling point, insert the sensor in water at that
temperature. Use an ohmmeter to read resistance value.
Part number 550-142-950/0122
-
wall mount gas fired water boiler
(continued)
–
boiler manual
Figure 115 Control circuit fuse location
Fuse located on rear of circuit board
Figure 116 Thermostat-relay circuit fuse location
Installer/homeowner
note, in case of an
"open circuit" of the
Thermostat-relay fuse the
boiler can run in DHW
mode but NOT in Central
Heating mode.
b
3. To check whether the FreeStyle® control is correctly sensing
temperature, you can use a resistance decade box. Connect
the decade box temporarily in place of a sensor and read the
corresponding temperature on the FreeStyle® control display.
The temperature should be close to the value corresponding
to the input resistance.
Figure 117 Sensor resistance values
Temp Temp
Sensor ohms
(°F) (°F)
Min Max
32 100
31530 33480
40 110
25792 27388
50 120
19258 20450
60 130
15218 16160
70 140
11577 12293
80 150
8891 9441
90 160
7185 7629
a
Temp
Sensor ohms Sensor ohms
(°F)
Min Max Min
170
5608 5954 1344
180
4590 4874 1143
190
3636 3860 945
200
3011 3197 810
212
2417 2567 657
-
1954 2074 -
-
1644 1746 -
Max
1428
1213
1003
860
697
-
-
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