1.2 Who is the manual for?
While this manual is primarily written for heating professionals, some of the content may be useful for
building managers and homeowners; for example, information about setting overrides.
1.3 Power-up sequence and operational states/cycles
When a boiler is first energized, the controller runs through a power-up sequence that takes
approximately 90 seconds. During this time, the controller completes a self-diagnostic, then loads all
previous settings. When power is restored after a power interruption, the boiler automatically resumes
operation with all the previously stored values.
The controller has five states during normal operation as well as an error state for problem detection:
Figure 3 Stages of controller operation
For a detailed work flow and sequence of operation, see Sequence of Operation - VX series boilers on
page 96.
1.2 Who is the manual for?