Bosch Therm 6000 S - Functional Scheme

between the right pair of wires when the unit is operating. If voltage is not
6 720 800 095 (2014/05) Therm 6000S
40 | Functional scheme
11 Functional scheme
Fig. 51
Fan speed
OK?
waiting
time of 10s
passed?
water tap
open?
Water flow
0.5 gpm
(> 1.9 l/min)
(see WF calc.)
>
NO
NO
NO
NO
YES
YES
YES
YES
ONONON
NO
YES
YES
Start sparking
IDLE
Open the gas
valve
1st
Safety time
of 5s passed?
Ionization
detected?
6720608158-65.2V
NO
NO
NO
NO
YES
YES
YES
See error
code table
Post purge of
fan for7sec.
Stay blocked
till RESET
close second
gas valve
Post purge of
fan for7sec.
water tap
closed
<0.5 gpm?
safety
devices
OK?
close one gas
valve
waiting
time of
1s passed?
flame off?
Hot water
delivered at
selected temp.
Appliance
ready to start?
Fan speed=correct
Ionization=off
Temp. limiter = closed
Temp. sensors=ok
Over heat protection=ok
See error code table
INPUTS:
- FANSPEED
- WATER TEMP.
- WATERFLOW
OUTPUTS:
- FANSPEED
- WATERFLOW
YES
YES
SEYSEY
2nd
Safety time of
5s passed?
3rd
Safety time
of 5s passed?
Water ow
Calculus
WF =
Burner ON
Burner ON
Minimum Power
(Set point-Inlet)
NO
YES
YES
Burner shutdown at:
Set point +9°F (5°C)
WF<0.45 gpm±0.05 gpm
(WF<1.7 l/min±0.2 l/min)
Burner shutdown at:
Set point +14°F (8°C)
WF<0.45 gpm ± 0.05 gpm
(WF < 1.7 l/min ± 0.2 l/min)
0.5 GPM<WF < 1.6 GPM
(2 l/min < WF <6 l/min)
WF > 1.6 GPM
(WF > 6 l/min)
NO
Water ow procedure