Rheem 70103 - Operational Flow Charts

11
TM063 701, 702 & 703 Series Boiling Water Unit Service Instructions
Revision D: Feb 2017
This document is stored and maintained electronically by Service. All printed copies not bearing this statement in RED are deemed “uncontrolled”
Operational Flow Charts
Operational Flow Chart – 701 & 702 Series
(7)
(4)
(2, 6)
Water drawn off
YES
(1)
Plug In
Power On
Fault rectified Isolate Power
NO
Inlet solenoid off
(if on)
Control board triac
(element) disabled
Control board
relay off
NO
Inlet solenoid on
Control board triac
(element) off (if on)
NO
Inlet solenoid
off after 30 seconds
Full ‘auto calibration’
cycle performed
Control board
relay on
Control board triac
(element) on 20% - 100%
NO
Water temp (Treq)
maintained at 0ºC
(element off)
NO
NO
Control board triac
(element) off
YES
NO
YES
YES
YES
YES
YES
Inlet solenoid on
Inlet solenoid off
YES
Inlet solenoid off
YES
YES
YESNO
NO YES
NO
Control board triac
(element) on 20% - 100%
YES
Notes:
(1) Control board relay on = Boiling water triac (element) circuit enabled.
(2) The PCB monitors for faults while ever the boiling water unit is operating.
(3) ‘Tb’ is the boiling point temperature detected during calibration; ‘Treq’ is the temperature the water will be maintained at;
‘T0’ is the water temperature detected by the boiling water thermistor.
(4) Calibration is automatically performed by the control board on initial power up. Calibration will take approx 18 - 30
minutes (depending upon capacity) during which time 2 heating cycles will be performed. The tap should not be operated
whilst calibration is being performed.
(5) When measured using a conventional multimeter the voltage will be approx. 48 – 240 VAC.
(6) Critical faults are; Hot Sensor O/C or S/C, Triac S/C & Level Probe shorted to earth.
(7) Control board relay off = Boiling water triac (element) circuit disabled.
Critical fault
detected?
Timer
button pressed?
High level probe
detecting water?
Timer ‘ON’
period reached?
Timer in ‘OFF’
period and AUTO
selected?
Sleep mode
period set?
TImer
button pressed?
High level probe
detecting water?
‘T0’ < 70°C
for 3.5 days?
High level probe
detects water?
‘T0' < ‘Tb’-3?
Low level probe
detects water?
Auto calibration
already
performed?
‘T0’ = ‘Treq’-2? ‘T0’ < ‘Treq’-3?
Error Code Displayed
Inlet solenoid off after
15 seconds (if on)
‘Treq’ value set
using ‘Temp
Override’?
NO
(3)
Reduced ‘auto
calibration’ cycle
performed
(5)
(3)
(3)
(3)
YES
(3)
‘Treq’ becomes ‘Tb’-3
‘Treq’ becomes ‘Tb’-2
Critical fault detected?
YES
NO
NO
(2, 6)
(3)
‘T0' = ‘Treq’?
Control board triac
(element) off
(3)
YES
NO
NO
NO
YES
NO
High level probe
detects water?
YES
NO
(3)
Water drawn off
Control board triac
(element) on 20% - 100%
YES
‘T0’ = 70°C?
NO
Control board triac
(element) off
YES
(3)
(5)
(5)
Low level probe
detects water?
NO
YES NO
YES
A
A