Rinnai E110CN, E110CP, E75CN 15.2.12Error, check actual flow temperature, check flow sensor NTC1

Installation & Servicing Instructions Rinnai E-Series

15.2.12Error 18

Temp	NTC 12K
°F	(12k:/77°F)

supply sensor T1 return sensor T2 DHW sensor T3 outside sensor T4 flue gas sensor T5

-4	98,000
-0.4	90,000
3.2	82,000
6.8	74,000
10.4	66,000
14	58,000
17.6	53,500
21.2	49,000
24.8	45,000
28.4	40,500
32	36,000
35.6	33,500
39.2	30,900
42.8	28,200
46.4	25,600
50	23,000
53.6	21,400
57.2	19,900
60.8	18,100
64.4	16,600
68	15,000
71.6	14,000
75.2	12,900
78.8	11,900
82.4	10,850
86	9,800
89.6	9,100
93.2	8,500
96.8	7,900
100.4	7,200
104	6,500
113	5,600
122	4,600
131	4,000
140	3,400
158	2,300
176	1,700
194	1,300
212	950

Resistance table NTC-Sensors

Signal maximum flow water temperature exceeded (T1 > 212°F).

check actual flow temperature

suddenly increase caused by completely hydraulic shut off of the boiler (filter, pump, thermostat valve, service valve)

check flow sensor NTC1

measure the resistance value (see table)

exchange defective part if necessary.

Change control unit when error persists

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