Operational Flow Chart - All Models; Hydroelectric Generator; Sv2 (Main Burner Safety Solenoid Valve); Ignition Module - Rheem 834 Series Service Instructions Manual

Operational Flow Chart – All Models
START
NO Hot tap open?
YES
Hydro electric generator
generates voltage
Flow sensor detects
water flow and pulses
voltage from TC to TC
Water flow rate
NO (flow sensor pulse)
> 3 L/m?
YES
TC initialised.
Green LED on
MASV driven to
minimum gas position
(1) Hot water outlet
temp sensor
< 20°C (cold start)
NO
Energise P700 ignition
module
False flame
detected ≥ 3 sec?
NO
Igniter pulse ignition
(spark) on
SV1 energised
Flame detected
(> 0.5 µA) within
45 seconds?
YES
Igniter pulse ignition
(spark) off
SV1 de- energised
SV2 & SV3 energised
after 4 seconds
Fault detected?
NO
(3) MASV adjusted
(Gas flow rate control)
Battery voltage
> 2.8 and < 3.5 VDC?
NO
Water flow rate
YES
> 2.7 L/m?
TM081 Rheem 834 Series Hydroelectric CFGWH Service Instructions
REV: AA Issued: 22/02/17
This document is stored and maintained electronically by Rheem Technical Support. All printed copies are deemed uncontrolled.
TC = Temperature Controller
Notes:
(1) Re cold start: Provided setpoint temperature is 60°C, battery voltage is >
3.1 VDC and water flow rate through the heater is > 6 L/m.
(2) Re: Red LED 6 flash fault. This fault will occur if a 15°C temp rise is not
detected by the hot water outlet temp sensor within 45 ~ 180 seconds from
main gas valve (SV2 & SV3) energisation (actual time is flow rate dependent).
(3) MASV is continually adjusted according to hot water outlet temp (as
detected by the hot water outlet temp sensor) and the heater's setpoint
temperature i.e. lower hot water temp = more gas. Note: If water flow rate
through heater is reduced by ≥ 1.4L/m, the pilot will light (SV1 energised), the
main burner will extinguish (SV2 & SV3 de-energised), the MASV will readjust
and the main burner will relight and pilot extinguish after a two second delay.
(4) Non critical faults: Battery disconnected or battery voltage ≤ 3.1 VDC
(green LED will continuously flash) or water throttle valve malfunction (red
LED will continuously flash, green LED will extinguish).
Note: water throttle valve
is de-energised when hot
water outlet temp sensor
detects ≥ 20°C or 12.5
seconds has expired
Energise water throttle
YES valve to reduce water
flow by 33 ~ 50%
YES
(Critical fault)
SV1 de-energised
Pilot Igniter pulse ignition
valve (spark) off
NO
(Critical fault)
NO
second loss of
flame fault within 1
water flow cycle?
Note: Pilot operates
on residual gas for
approx 6 seconds
YES
Main
burner
valves
Is fault loss of
YES
flame?
NO
(4) Is fault a non
YES
critical fault?
Battery recharge
YES function on until battery
voltage is 3.5 VDC
TC determines shut
NO down due to low water
This is not
flow (or hot taps closed)
a fault
LED indication removed
Was a critical fault
detected?
MASV driven to
NO
minimum gas position
YES
Battery voltage
> 3.1 VDC?
Water valve de-
energised (if on)
Battery recharge
off (if on)
De-energise P700

ignition module

SV2 & SV3
de-energised
A A
YES
(Critical fault)
(Critical fault)
NO
(Critical fault)
TC green LED will
Note: Pilot operates
extinguish whilst
on residual gas for
charging is in
approx 6 seconds
progress
Hydro electric generator
ceases to generate
voltage
Hydro electric generator
ceases to generate
voltage
Flow sensor detects no
water flow and ceases
pulse generation
YES
Hot taps closed?
NO
NO
Overheat switch
YES open circuit
Red LED 1 flash
P700 ignition circuit
abnormal
Red LED 2 flash
SV3 / MASV faulty
Red LED 3 flash
False flame, ignition
failure or loss of flame
Red LED 4 flash
Hot water outlet temp
sensor abnormal
Red LED 5 flash
(2) Main burner circuit
abnormal
Red LED 6 flash
Hot water outlet temp
sensor detects ≥ 85°C
Red LED 7 flash
SV2 & SV3
de-energised
MASV driven to
minimum gas position
Igniter pulse ignition
(spark) on
Pilot
SV1 energised
valve
Flame detected
NO
(> 0.5 µA) within
45 seconds?
YES
Igniter pulse ignition
(spark) off
SV1 de- energised
Main
SV2 & SV3 energised
burner
after 4 seconds
valves
14