UHD L
OW
P
ROFILE
D
UCT
F
URNACE
I
NSTALLATION
O
PERATION
AND
S
ERVICE
M
ANUAL
30 of 47
Fi
g
ure 17: Manual Reset Limit Switch
12.3 Li
g
htin
g
Instructions
12.3.1 To Turn On Heater
1. Ens
u
re that the electrical and gas s
u
pplies to
the heater are on. Check that the on site
controls are "ON".
IMPORTANT:
The thermostat setting m
u
st be above
the ambient temperat
u
re for the heater to operate.
2. The a
u
tomatic firing seq
u
ence
w
ill begin as
described
on Page 27, Figure 15
. The heater
w
ill no
w
operate a
u
tomatically
u
nder the control
of the on site controls.
12.3.2 To Turn Heater Off
Set the thermostat to the "OFF" position.
The b
u
rner
w
ill t
u
rn off immediately.
To restart, t
u
rn the thermostat above room
temperat
u
re.
12.4 Simple Troubleshootin
g
Some possible reasons for the heater not operating
are:
1. Gas s
u
pply not "ON".
2. Electricity s
u
pply not "ON".
3. The time and/or temperat
u
re controls are not
"ON".
4. A limit s
w
itch may have operated. This may be
ca
u
sed by an interr
u
ption of the electrical
s
u
pply, fail
u
re of the distrib
u
tion fan or vent or
heat exchanger blockage.
If a temperat
u
re limit s
w
itch persistently trips, there
is a fa
u
lt
w
hich m
u
st be investigated by a contractor
q
u
alified in the installation and service of gas-fired
heating eq
u
ipment.
12.4.1 Simple Troubleshootin
g
(Burner Faults)
If the b
u
rner fails to ignite for any reason, it
w
ill retry
for ignition (fo
u
r trials total). After fo
u
r
u
ns
u
ccessf
u
l
ignition trials, the control
w
ill p
u
t the heater into
locko
u
t for one ho
u
r.
Locko
u
t sho
u
ld not occ
u
r d
u
ring normal operation of
the heater and indicates there is a fa
u
lt condition
w
hich m
u
st be corrected. There is an LED light on
the ignition control that flashes codes to assist in
fa
u
lt correction.
See Page 30, Figure 18
for LED
indication codes.
Fi
g
ure 1
8
: LED Dia
g
nostic Codes
Reset Button
To reset man
u
al reset limit s
w
itch, press reset
b
u
tton.
NOTE:
To reset, the s
w
itch m
u
st be cool.
Description
Part Number
Man
u
al Reset Limit S
w
itch
90412106
LED INDICATION FAULT MODE
Slo
w
Flash
Normal Operation - No call for heat.
Fast Flash
Normal Operation - Call for heat.
2 Flashes
Ignition Locko
u
t - No flame detected.
3 Flashes
Airflo
w
Fa
u
lt - Press
u
re s
w
itch open or closed.
4 Flashes
Temperat
u
re Limit or
Man
u
al Reset Limit S
w
itch Open
5 Flashes
Flame Sense Error - Gas valve not energized.
Steady On
Internal Control Fail
u
re
Summary of Contents for Combat UHDXS 100
Page 2: ......
Page 4: ......
Page 6: ......
Page 8: ......
Page 29: ...SECTION 9 GAS PIPING 21 of 47 Figure 14 Gas Connection ...
Page 43: ...SECTION 14 TROUBLESHOOTING 35 of 47 14 1 General ...
Page 54: ...UHD LOW PROFILE DUCT FURNACE INSTALLATION OPERATION AND SERVICE MANUAL 46 of 47 ...
Page 56: ......
Page 57: ......
Page 58: ......
Page 59: ......
Page 60: ......
