Freestyle 80 - Checking Temperature Sensors

Part number 550-142-850/0716
83
FreeStyle
®
WALL MOUNT GAS-FIRED WATER BOILER — Boiler Manual
32 Troubleshooting(continued)
Temp
(°F)
Sensor ohms
Temp
(°F)
Sensor ohms
Temp
(°F)
Sensor ohms
Min Max Min Max Min Max
32
31530 33480
100
5608 5954
170
1344 1428
40
25792 27388
110
4590 4874
180
1143 1213
50
19258 20450
120
3636 3860
190
945 1003
60
15218 16160
130
3011 3197
200
810 860
70
11577 12293
140
2417 2567
212
657 697
80
8891 9441
150
1954 2074
-
--
90
7185 7629
160
1644 1746
-
--
Check flame signal
1. Navigate to Diagnostics/Inputs on the FreeStyle ® control
display (see pages 60 to 64FORNAVIGATIONINSTRUCTIONS
2. 4HEmAMESIGNALVALUEMUSTBEATLEASTONLOWlRE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EQUALSMICROAMPSOFmAMESIGNAL)FTHEmAME
signal drops below this level, the FreeStyle ® control will at-
tempt to correct by increasing the blower speed to increase
flame signal.
3. !LOWmAMESIGNALMAYINDICATEAFOULEDIGNITORORDAMAGED
ignitor cable insulation.
a. See “Inspect ignition electrode,” page 103 to remove and
inspect the ignitor.
b. )FREQUIREDCLEANTHEIGNITORANDmAMERODASINSTRUCTED
see page 103.
c. )FCLEANINGTHEIGNITORDOESNOTIMPROVEGROUNDWIRING
ISINGOODCONDITIONANDGROUNDCONTINUITYISSATISFAC-
tory, replace the ignitor.
4. )FmAMESIGNALSTILLREMAINSLOW
a. Inspect the vent and air piping.
b. Check combustion values.
c. 4HEN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 103).
d. #LEANTHEHEATEXCHANGERASDESCRIBEDINTHISMANUALIF
necessary, see page 106.
Check control fuse
 !,7!93CHECKCIRCUITFUSESBEFOREREPLACING
control or any major components (blower, etc.).
)FAFUSEISBLOWNITCANPREVENTTHE FreeStyle ®
CONTROLOROTHERCOMPONENTSFROMOPERATING
1. Turn OFF power to boiler at external line switch. Then
remove the jacket door.
2. ,OCATEFUSESUSINGFigure 106 and Figure 107.
3. 2EMOVEANDINSPECTTHEFUSES)TEMAFigure 106 or Item
b, Figure 107).
4. )FNECESSARYREPLACETHEFUSES
a. #ONTROLCIRCUITFUSEISA6!#AMPRATEDFUSE
,ITTELFUSE0
b. 4HERMOSTATRELAYCIRCUITFUSEISA6OLTM!RATED
FUSE,ITTELFUSE4YPEXMM
 $ONOTJUMPERFUSESORREPLACEWITHANYFUSEEXCEPT
as specified. Failure to comply could result in se-
vere 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 108
SHOWSTHECORRECTVALUEFORTHESENSORATVARIOUSTEMPERA-
TURES&OR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.
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 106#ONTROLCIRCUITFUSELOCATION
&IGURE 4HERMOSTATRELAYCIRCUITFUSELOCATION
Figure 1083ENSORRESISTANCESVALUES
Installer/homeowner note,
INCASEOFANhOPENCIRCUITv
OFTHE4HERMOSTATRELAY
FUSETHEBOILERCANRUNIN
DHW mode but NOT in
Central Heating mode.
Fuse located on rear of circuit board
a
b