Thermal Solutions APEX APX425C Installation, Operating And Service Instructions page 89

10
Operation
(continued)
4. Modulation Parameters
Asphyxiation Hazard.
Boiler type is factory set and must match the boiler model. Only change the boiler type setting if you are
installing the boiler at altitudes above 2,000 ft. or if you are replacing the control. The boiler type setting
determines minimum and maximum blower speeds. Incorrect boiler type can cause hazardous burner
conditions and improper operation that may result in PROPERTY LOSS, PHYSICAL INJURY, OR DEATH.
Select to access the following parameters.
Parameter and Description
Boiler Model
To verify the boiler model selection, a qualified technician should do the following:
1. Check boiler's label for actual boiler model.
2. Set "Boiler Model" to match actual boiler model.
3. Select "Confirm".
The Boiler Model parameter changes the minimum and maximum modulation
settings. This parameter is intended to allow a user to set parameters for altitudes
above 2,000 ft. or in a spare part control to a particular boiler model. See Figure
10-19.
CH Max Modulation Speed
This parameter defines the highest modulation rate the control will go to during a
central heat call for heat. If the rated input of the installed radiation is less than the
maximum output of the boiler, change the Central Heat Maximum Modulation (fan
speed) setting to limit the boiler output accordingly.
DHW Max Modulation Speed
This parameter defines the highest modulation rate the control will go to during
a Domestic Hot Water call for heat. If the rated input of the indirect water heater
is less than the maximum output of the boiler, change the DHW Maximum
Modulation (fan speed) setting to limit the boiler output accordingly.
Minimum Modulation Speed
This parameter is the lowest modulation rate the control will go to during any call
for heat.
Lightoff Rate
This is the blower speed during ignition and flame stabilization periods.
NOTICE: If boiler is being installed at elevation above 2,000 ft., refer to Appendix A: Instructions for High
Altitude Installations Above 2,000 ft.
106308-05 - 3/23
!
WARNING
Figure 10-19: Boiler Model (Boiler Type) Decoding
APEX Installation, Operating, & Service Instructions
Factory
Setting
varies by model
varies by model
80% of CH
Maximum
Modulation
Speed
varies by model
varies by model
Range / Choices
see Figure 10-19
Minimum to Maximum
Modulation
Minimum to Maximum
Modulation
Minimum to Maximum
Modulation
425: 3,500-4,000 rpm
525-825: non-adjustable
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