TM090 12-26 Series II CFGWH Service Instructions
REV AB
– Issued February 2019
This document is stored and maintained electronically by Rheem Technical Support. All printed copies
are deemed “uncontrolled”
11
Sequence of Operation Component Diagram
1
Hot Water Tap
2
Bypass pipe
3
Water Flow Sensor
4
Inlet Water Temperature Thermistor
5
Combustion Chamber Thermistor
6
Outlet Water Temperature Thermistor
7
Water Flow Servo Motor
8
Water Filter (Strainer)
9
Gas Inlet Solenoid Valve
10
Gas Solenoid Valve 1
11
Gas Solenoid Valve 2
12
Gas Solenoid Valve 3
13
PGFR Valve
14
Nozzle
15
Burner
16
Igniter
17
Igniter Electrode
18
Flame Sensor
19
Heat Exchanger
20
Over Temperature Limiter
21
Exhaust (Flue) Outlet
22
Combustion Chamber
23
Anti Frost Heater (Models with F in
model number only e.g. 874826NF)
24
Fan
25
Fan Motor
26
Drain Plug With Relief Valve.
27
PCB
Burner Configuration (Burner Change-Over Assembly)
Burner 1
Burner 2
Burner 3
Centre Solenoid (S.V. 2)
Left Solenoid
(S.V. 1)
Right Solenoid
(S.V. 3)
Stepping gas rate change sequence by solenoid
Step 1
Step 2
Step 3
Step 4
Step 5
Step 6
SV. 2 ON
SV. 3 ON
SV. 2 & 3 ON
SV. 1 ON
SV 1 & 2 ON
SV 1,2 & 3 ON
Flame Sensor Status
Power
0
1
2
3
4
5
6
R0y Information
00
01
01
01
10
11
11
Flame Sensor 1
X
O
O
O
X
O
O
Flame Sensor 2
X
X
X
X
O
O
O
Solenoid Valve1
OFF
OFF
OFF
OFF
ON
ON
ON
Solenoid Valve2
OFF
ON
OFF
ON
OFF
ON
ON
Solenoid Valve3
OFF
OFF
ON
ON
OFF
OFF
ON
X
= Flame sensor is not detecting flame.
O
= Flame sensor is detecting flame