Pump Start Every 24 Hours (Rev 3.0.0.0); Frost Protection (Rev 3.0.0.0) - Bosch SSB1000 SA Manual

The following table shows the sensor availability for all CH and DHW
control modes. Sensors that are not mentioned in the table are optionally
available for other functions.
0
T_Supply M
T_Supply_2 -
T_Return -
T_DHW -
T_Outdoor D
0-10 Volt -
Water Flow DHW -
RT switch M
0 1
T_Supply - M
T_Supply_2 - -
T_Return - -
T_DHW D M
T_Outdoor - -
0-10 Volt - -
Water Flow DHW - -
RT switch - -
Legend:
M Mandatory
- Optional
D Disabled
The T_Flue and T_Flue_2 sensors do not store the sensor open error.
This is to protect the system going to a blocking state in very cold
conditions.
SSB
CH mode
1 2 3 4
M M M M
- - - -
- - - -
- - - -
M M -
- - - M
- - - -
M M M M
DHW mode
2 3 5 6 7
M - - M M
- - - M -
- - - D -
D M M M D
- - - D D
- - - - -
- - M - M
M - - - -
5 .3 .6 Pump start every 24 hours (Rev 3 .0 .0 .0)
To protect the pump from getting stuck at a certain position it is forced to
run for 10 seconds every 24 hours. This is done only for the CH pump at
the start-up of the board.
5 .3 .7 Frost protection (Rev 3 .0 .0 .0)
The frost protection function protects the system from freezing.
The T_Supply , T_Supply_2 and T_Return sensors are checked for
generating a frost protection demand.
• When any of the sensors drop below FP_start_pump the pump is
switched on for CH.
• When any of the sensors drop below FP_start_burn the burner is
started.
• When all of the sensors measure above FP_stop the frost protection
demand is ended.
When the demand for frost protection is ended the pumps will post-
8
circulate for CH_Post_Pump_Period . Relevant variables
M
-
Relevant variables
M
M
Specific Parameters Level
-
FP_start_pump
-
[°C/°F]
FP_start_burn
M
[°C/°F]
E2_FP_stop
-
[°C/°F]
5 . 3 . 7 . 1 Frost protection
In cascade systems frost protection is active on 3 levels.
[4] Boiler cascade controller
[5] Burner cascade controller
[6] Burner
The start temperatures should be defined so that the cascade handlers
are the first to trigger the protection. When there is a CH/DHW call for
heat, the frost protection will be overridden and the control will start for
CH/DHW. When frost protection stops the pumps go to post purge.
The display may show "Frost protection" when it is activated.
Specific Parameters Level
Cascade frost
protection
[°C/°F]
Temperature for frost
protection
Frost protection for boiler cascade
The 'frost protection' function for a boiler cascade is related to the system
sensor temperature.
When the system sensor temperature is below:
Cascade frost protection
The cascade CH/system pump and the general pump of the managing
burner in the managing boiler start running.
Main control | 35
(Default) Value Settable
°C °F °C
3: Factory 10 50 -10..117 14..243
3: Factory 5 41 -10..117 14..243
3: Factory 15 59 -10..117 14..243
(Default) Value Settable
°C °F °C
2: Installer 15 59 10..30
6720892984 (2019/02) US
°F
°F
50...86