Bradford White IGI-180R-10 Service Manual page 40

VI - TROUBLESHOOTING
BEFORE CARRYING OUT CHECKS MARKED WITH A # SIGN, DISCONNECT THE POWER SUPPLY.
6) Is the main gas solenoid valve (SV0) operating normally ?
7) Is the change over solenoid (SV1) operating normally ?
8) Is the change over solenoid (SV2) operating normally?
(cont.)
If error "11" or "71" is displayed, check the main gas solenoid
valve.
a. # Disconnect the main gas solenoid valve (SV0)
connector and measure the resistance at the solenoid
terminals.
Normal: 1.7 ~ 2.1 K Ω
If normal, check b below.
Faulty: Replace gas valve.
(Service Procedure IGI-9, page 52)
b. Measure voltage at the main gas solenoid (SV0)
Pink and black wires.
Normal: 80 ~ 100 VDC
If normal, proceed to check item 7 below.
Faulty: Replace PCB unit.
(Service Procedure IGI-2, page 49)
If error "11" or "71" is displayed, check the change over
solenoid (SV1).
a. # Disconnect the change over solenoid (SV1)
connector, and measure resistance at the solenoid
terminals.
Normal: 1.7 ~ 2.1 K Ω
If normal, check b below.
Faulty: Replace the gas valve.
(Service Procedure IGI-9, page 52)
b. Measure voltage at the change over solenoid
(SV1) yellow ~ black wires.
Normal: 80 ~ 100 VDC
If normal, check 8 below.
Faulty: Replace PCB unit.
(Service Procedure IGI-2, page 49)
If error "11" or "71" is displayed, check the change over
solenoid (SV2).
a. # Disconnect the changeover solenoid (SV2) connector,
and measure the resistance at the solenoid terminals.
Normal: 1.7 – 2.1 K Ω
If normal, check b below.
Faulty: Replace the gas valve.
(Service Procedure IGI-9, page 52)
b. Measure the voltage at the changeover solenoid (SV2),
blue – black wires.
Normal: 80 – 100 VDC
If normal, check 9, on next page.
Faulty: Replace the PCB unit.
(Service Procedure IGI-2, page 49)
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