Velocity Shadow Series, Installation And Operating Instructions Manual

Page: 81 / 104

80
FIGURE 14.5: TROUBLESHOOTING BLANK DISPLAY
START
Is display
completely
dark?
 Verify that display is not still in
power ‐ up ” process (Figure
11.2a)

Loose or mis ‐ wired
connection between the
display and terminal J3 on the
boiler control
 Defective display
Is boiler control’s green
power light on?
Is boiler fan
running at high
speed?
Is 120V present across
black and white boiler
line voltage
connection leads?
Is 24VAC present
between J8 ‐ 1 and J8 ‐ 2
(blue and yellow)
terminals on boiler
control?
Is 24VAC present
across transformer
secondary (brown and
pink wires at plug L3?)
Is 120VAC
present across
black and white
wires at plug L2?
 Loose or mis ‐ wired
connection between the
display and terminal J3 on
the boiler control

Defective display

Open fuse or breaker at
main panel

Loose or mis ‐ wired
connection between main
panel and boiler.

Defective boiler control
 Loose plug L2

Defective
transformer –
look for short
circuit in 24V
wiring
 Loose plug P1

Loose plug P3
 Loose connection
between L3 and J8
See Figures 10.5 and 10.6 for
the location of connectors
referenced here
Y
N
Y
N
Y
N
Y
N
Y
N
Y
N
Y
N