APPENDIX A
HeatNet Control REV 1.38-1
Page 77
AIR SWITCH:
If the IGNITION control closes its blower relay, the control
does not see the PILOT relay close within (2) minutes, and
the AIR PRESSURE switch is made, this message will be
displayed. This alarm protects the boiler from freeze ups
being caused by a blower bringing in cold outside air with
no fire.
STACK TEMPERATURE:
If the boiler’s stack temperature exceeds 550°F this message
will be displayed. If the stack temperature continues to rise
above 700
°F the boiler will be held in low fire.
CALL SERVICE:
If the H-Net control closes the last interlock string entering
the ignition control and the ignition control never closes its
Blower Relay, the H-Net control will wait 2 minutes. The
H-Net control will then retry for the duration of the local
pump post purge time and then retry the ignition sequence.
During this time “retry strt” will be displayed in the status
screen. After (5) attempts the H-Net control will lock out
and display call service.
