LAARS IGE-199C-5(N,X) - Service Manual - Manual (Page 26)

VI - TROUBLESHOOTING (cont.)
Thermal Fuse:
Red ~ Red 100 VAC Below 1 ohm B ~ C B6
~ C1
Overheat Switch:
Red ~ Red 100 VAC Below 1 ohm B ~ C B6
~ C1
Flame Rod:
Place one lead of your meter to the flame rod and the other to earth or ground. With the unit running
you should read between 5 ~ 150 VAC. Set your meter to the µ amp scale, series your meter in line
with the flame rod. You should read 1µ or greater for proper flame circuit. In the event of low flame
circuit remove the flame rod and check for carbon and/or damage.
Heat Exchanger, Air Temperature, and Outgoing Water Temperature Thermistors:
Check all thermistors by inserting meter leads into each end of the thermistor plug. Set your meter to
the 20K scale and read resistance. You should be able to apply heat to the thermistor bulb and see
the resistance decrease. Then apply some ice to the thermistor and the resistance should increase.
See below for examples of temperatures and resistance reading at those temperatures.
Example: 59°F = 11.4 ~ 14K
86°F = 6.4 ~ 7.8K
113°F = 3.6 ~ 4.5K
140°F = 2.2 ~ 2.7K
221°F = 0.6 ~ 0.8K
Outgoing Water Thermistor:
White ~ White N/A See example above B B3 ~ B4
Heat Exchanger Temperature Thermistor:
White ~ Pink at board N/A See example above B B3 ~ B12
Surge Protector:
Black ~ White 108
~ 132 VAC
N/A Surge Protector D
1
1 ~ 3
Blue ~ Brown 108
~ 132 VAC
N/A Surge Protector D
2
1 ~ 2
With the power off you can check the continuity through the surge protector. Place one meter lead on
the top pin #1 of the surge protector and pin #2 on the bottom of the surge protector. Then check
across top pin #3 and bottom pin #1, if you read continuity across these two points the surge
protector is good. If you do not get continuity, replace the surge protector.
Remote Controls:
Terminals D
1
10 ~ 13 VDC digital 1.5K ~ 1.9K ohms H 1 ~ 3
Frost Protection:
This unit has four frost protection heaters mounted at different points inside the unit to protect the
water heater from freeze ups. There are two heaters located on the outlet hot water line next to the
thermistor.
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