Therma Grow™ Greenhouse Heaters
www.lbwhite.com
Owner’s Manual • Therma Grow™
26
Are ai
r-p
ro
ving switch
contacts stuck open? (
Pe
rform continuity
chec
k.)
Does
fan m
ot
or sta
rt up
for prepurge
during initial call
for heat?
Is
fan wheel bindin
g?
Is
fan wheel
lo
os
e o
n m
ot
or
sha
ft?
Ye
s
Ye
s
Ye
s
No
Check
for binding of
ai
r-p
ro
ving switch arm
on housing,
Repair or
replace as necessa
ry
.
Ye
s
Ye
s
Check
for p
roper clearance of
fan wheel
to
m
ot
or mount. If
good, replace
fan wheel, or
check
for housing alignment.
Tigh
ten set scr
ew(s) on
fan. Ma
ke
sure set scr
ew(s) are tigh
te
ne
d
against flat(s) of m
ot
or sha
ft.
Ye
s
Clean the
fan wheel with
co
m
pressed air or so
ft brush.
Ye
s
Re
m
ov
e obstruction.
Clean as necessa
ry
.
No
Is
fan wheel
plugged with
di
rt?
Is there an obstruction
in bl
ow
er outlet pr
ev
enting
ai
r-p
ro
ving switch closure?
No
Are
11
5
volts sent
from ignition
cont
rol
terminal
IND
to
m
ot
or rel
ay
No
If i
m
pr
oper
voltage is supplied,
contact electrician.
- OR -
If no
voltage is supplied
to
m
ot
or
rel
ay , check wiring b
ewt
w
ee
n
m
ot
or rel
ay and ignition cont
rol. If
good, replace cont
rol.
No
Ye
s
Are
24
volts supplied
from
terminal PS1
on cont
roller
to the
air p
ro
ving switch?
Check wiring bet
w
een module and
co
m
ponent.
Repair or replace as
necessa
ry
. If wiring is good, replac
e
ignition cont
rol module.
No
Is
voltage sent f
ro
m
rel
ay
to
m
ot
or?
Check wiring bet
w
ee
n
rel
ay and m
ot
or
. If
de
fecti
ve, repair as
needed. If good,
replace rel
ay
No
Ye
s
De
fecti
ve
m
ot
or
.
Replace m
ot
or
.
Ye
s
Are
24
volts returned
from air p
ro
ving
switch
to
terminal
PSO on cont
roller?
No
De
fecti
ve ignition
cont
rol.
Replace
ignition cont
rol.
No
No
De
fecti
ve air p
ro
ving switch.
Replace switch.
Tw
o
Ti
m
es
Flash pat
tern
begins 12 seconds a
fter
condition occu
rs.
(Pat
tern
indica
tes
la
ck of air
pr
oving in fan
section of unit.)