Rinnai REU-24 W-A Service Manual page 51

Remove one (1) incoming water
temperature thermistor securing screw.
CAUTION: Avoid losing the 0 ring.
8. Removal of the ANTI-FROST HEATER
HARNESS ASSEMBLY
CAUTION: 240 Volt exposure. Isolate the
electrical and water supplies to the
appliance, reconfirm with a neon
screwdriver or multimeter.
Drain appliance - see page 42.
Follow section 1 first.
Follow section 7 steps a + q.
9. Removal of the COMBUSTION FAN
CAUTION: 240 Volt exposure. Isolate the
electrical, gas, and water supplies to the
appliance, reconfim with a neon
screwdriver or multimeter.
Drain appliance - see page 42.
thermistor
1
Follow section
Remove P.C.B. Unit. Follow section 2.
a.
b. Remove hot water supply connection tube
and water bypass distributor. Follow section
6 steps a + c.
Remove harness B assembly. Release the
C.
heat exchanger outlet thermistor connector,
outgoing water temperature thermistor,
flame rod connector, sparker festoon
terminal connectors, water flow sensor
connector.
E.W.F.C.D. connector, incoming water
temperature thermistor, thermocouple yellow
connector. Harness should be free now.
d. Release anti-frost heater connector (white -
white), thermal fuse connector, and
incoming electrical supply connector.