Rinnai RHFE-551FA Service Manual page 29

Troubleshooting
(SV1, SV2, SV3) Gas valve solenoids
SV1 - Purple - Yellow
SV2 - Purple - Peach
SV3 - Purple - Yellow
(BL) Combustion Fan 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
White - yellow = low speed
White - red = high speed
(FM) Convection fan motor:
White - blue = low speed
White - red = high speed
(TR1) Transformer
Black - White
Red - Black
(PS) Pressure switch:
White - Ground
Check from both white wires to
ground to ensure circuit is
complete.
(RT) Slide temperature control:
To check slide thermostat, set your meter to the 200k ohm scale. By reading across the red and red wires
you should have an ohm reading from 0 to 30k ohms from high to low.
(TH) Thermistor:
Check thermistor by inserting meter leads into each end of 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 resistance
decrease. Then apply some ice to the thermistor and the resistance should increase.
EXAMPLES: 41 °F = 91 k ohms
50 °F = 65 k ohms
68 °F = 39 k ohms
86 °F = 23 k ohms
90 VDC Lo fire
90 VDC Hi fire
90 VDC redundant coil
95 - 105 VAC
95 - 105 VAC
95 - 105 VAC
95 - 105 VAC
110 - 125 primary side
98 - 105 secondary side
9 - 12 VDC
Rinnai Direct Vent Service Manual
1,200 - 1,800 ohms
1,200 - 1,800 ohms
1,200 - 1,800 ohms
200 - 300 ohms
120 - 180 ohms
230 - 290 ohms
100 - 125 ohms
16 - 21 ohms
24 - 29 ohms
In order to eliminate this switch as a cause of
failure, shut the power off to the unit and
jump out this switch. Restart unit. If it
functions, replace air pressure switch.
RHFE-551FA
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