Control Operations Guide
Bosch Buderus SSB255 | SSB399 | SSB512 Boilers
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Bosch Thermotechnology Corp.
|
03.2018
Data subject to change
8 Start-up & Commissioning Settings
Parameter
Description
Frost Protection
(parameter #89)
Default setting for Frost Protection is “Disabled”. When “Enabled” Frost Protection Setpoint will be actived when the
temperature of the supply or return water sensor reaches Frost Protection Setpoint (see parameter
#90 below).
Frost Protection Setpoint
(parameter #90)
When the Supply or Return water temperature of the boiler reads temperatures below the value of Frost Protection
Setpoint, both the Boiler and CH pump contacts will be energized. Should the temperature continue to fall an
additional 9 degrees below the value of Frost Protection Setpoint the burner will start and operate at minimum
power until both Supply and Return temperature sensors measure 9 degrees above the original Setpoint value of
Frost Protection. Default value is 50°F and the parameter is adjustable from 34°F to 68°F.
DHW Max. Limit
(parameter #37)
The maximum temperature limit for the domestic hot water. Default value is 140 °F. Adjustable range from 104 °F to
158 F. Note: Use parameter #48 to set the actual desired DHW temperature. This parameter is used to limit the user
from being able to increase the domestic hot water temperature.
Fan Speed Maximum
(parameter #92)
Maximum fan speed RPM – based upon Parameter #97 Appliance Model and Parameter #98 Gas Type (see below).
This parameter is factory set and should not be adjusted.
Fan Speed Minimum
(parameter #93)
Minimum fan speed RPM – based upon Parameter #97 Appliance Model and Parameter #98 Gas Type (see below).
This parameter is factory set and should not be adjusted
Fan Speed Ignition
(parameter #94)
Ignition Fan Speed is set based upon shorter exhaust/air-intake lengths. As your combined equivalent lengths
increase the total straight length of pipe, number of fi ttings and pipe diameter may require higher ignition fan
speeds. Altitude will also impact necessary fan speed at ignition. See Venting section of the installation manual
for details. Initial fan speed is set by selecting the appropriate value for parameter #99 (Flue Length Range) once
selected based upon installation specifi cs parameter #94 may be used to make smaller adjustments to the fan RPM.
This parameter is factory set and should not be adjusted
Appliance Model
(parameter #97)
The value for this parameter is based upon the Model SSB Boiler.
SSB512 = 1
SSB399 = 2
SSB255 = 3
SSB160 = 4
SSB120 = 5
SSB85 = 6
Ensure the value for this parameter is set correctly for your model
Gas Type
(parameter #98)
Set gas type to the appropriate value.
NG = Natural Gas
LP = Liquid Propane Gas
Flue Length Range
(parameter #99)
During commissioning, the value for Flue Length range must be set based upon the equivalent length of exhaust/air-
intake pipe installed. See the Venting section of the installation manual for calculating the appropriate Flue Length
Range based upon Model boiler installed, the straight length of pipe, number and type of fi ttings, the pipe diameter
and the altitude of the installation. Refer to the installation manual, section 4.7.4 for fl ue length parameter ranges.
Table 19
