Bradford White TG-199E-N - Manual (Page 37)

37
Troubleshooting – Electrical
There are a number of (live) tests that are required when fault finding this product. Extreme care should
be used at all times to avoid contact with energized components inside the water heater. Only trained
and qualified service technicians should attempt to repair this product. Before checking for resistance
readings, disconnect the power source to the unit and isolate the item from the circuit (unplug it).
Table 11. (SV1, SV2, SV3, and POV) Gas Valve and Modulating Solenoids (Set Meter Above 2k).
Wire Color Voltage Resistance
Connector
No.
Pin
Nos.
(Main) Pink-Black 11-13 VDC 36.8-44.8 ohms H5 6-7
(SV1) Black-Yellow 11-13 VDC 36.8-44.8 ohms H6 5-6
(SV2) Black-Blue 11-13 VDC 36.8-44.8 ohms H7 4-6
(SV3) Black-Brown 11-13 VDC 36.8-44.8 ohms H8 3-6
(POV) Pink-Pink 2-15 VDC 67-81 ohms H3 9-10
Table 12. (M) Water Flow Control Device Servo or Geared Motor.
Wire Color Voltage Resistance
Connector
No.
Pin
Nos.
Red-Blue 11-13 VDC 22-28 ohms F7 9-10
Grey-Brown 4-6 VDC n/a F7 5-7
Grey-Yellow n/a n/a F7 5-8
Note: The grey wire listed above turns to black at F connector on the PCB.
Table 13. (QS) Water Flow Sensor.
Wire Color Voltage Resistance
Connector
No.
Pin
Nos.
Black-Red 11-13 VDC 5.5-6.2k ohms F2 1-3
Yellow-Black 4-7 VDC 1-1.4 Mega ohms F2 2-3
Table 14. By-pass Flow Control (By-pass Servo Model Only).
Wire Color Voltage Resistance
Connector
No.
Pin
Nos.
Brown-White
2-6 VDC (unit
in operating
mode)
15-35 ohms
G1 1-5
Orange-White G1 2-5
Yellow-White G1 3-5
Red-White -
Ground
G1 4-5
Table 15. (IG) Ignition System.
Wire Color Voltage Resistance
Connector
No.
Pin
Nos.
Grey-Grey 90-110 VAC n/a C1 1-2
Table 16. (FM) Combustion Fan Motor.
Wire Color Voltage Resistance
Connector
No.
Pin
Nos.
Red-Black 6-45 VDC n/a E1 1-2
White-Black 5-10 VDC 9.2-9.4k ohms E1 2-4
Yellow-Black 11-13 VDC 3.5-3.9k ohms E1 2-3
Set your meter to the hertz scale. Reading across the white and black wires at terminals 2 and 4 you should read
between 60 and 420 hertz.