Rinnai RHFE-551FA Service Manual page 22

Troubleshooting
(POV, SV1, and SV2) Gas valve solenoids:
WIRE COLOR
Gray - Gray
Black - Yellow
*Remember, when reading the resistance of a solenoid coil, you should read across the lugs on the coil.
(BL) Combustion Motor:
NOTE: If your meter does not have a hertz scale,
please refer to voltage and resistance
readings listed below. If you have a hertz
scale, check the following items first.
Hertz reading across black - white wires,
pins 41 and 42.
Voltage and resistance check for (BL).
WIRE COLOR
Red - Yellow
Black - White
(FM) Convection fan motor:
WIRE COLOR
Red - Gray
(TH) Thermistor:
Check the thermistor by inserting meter leads into each end of the thermistor plug. Set your meter to the 200k
scale and read resistance. You should be able to apply heat to the thermistor bulb and see the resistance
decrease. Then apply ice to the thermistor bulb and the resistance should increase. Pins 5 and 6 on the P.C.
board.
EXAMPLES: 41 ºF = 91 k ohms
50 ºF = 65 k ohms
68 ºF = 39 k ohms
86 ºF = 23 k ohms
22
VOLTAGE
4.5 VDC low fire to
11.5 VDC high fire
85 - 90 VDC
RHFE-431 - LP UNITS
RHFE-431 NG UNITS
VOLTAGE
1-2 VDC low fire to 7.6
-18 VDC high fire
N/A
VOLTAGE
80-94 VAC low fire to
95-104 VAC high fire
Rinnai Direct Vent Service Manual
RESISTANCE
80 - 100 ohms
1,300 - 2,000 ohms
Lo fire - 46 Hz.
Hi fire - 82 Hz.
Lo fire - 62 Hz.
Hi fire - 81 Hz.
RESISTANCE
1.2 - 1.8 mega ohms
9.4 k - 9.9 k ohms
RESISTANCE
90-180 ohms
RHFE-431WTA
RHFE-556WTA
PIN NO.
45 - 47
35 - 38
RHFE-556 LP UNITS
Lo fire - 47 Hz.
Hi fire - 106 Hz.
RHFE-556 NG UNITS
Lo fire - 48 Hz.
Hi fire - 106 Hz.
PIN NO.
43 - 44
41 - 42
PIN NO.
19 - 20